diff --git a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshI.H b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshI.H
index 9d71ce889c..1b46067c20 100644
--- a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshI.H
+++ b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshI.H
@@ -468,8 +468,8 @@ inline Foam::List<Foam::label> Foam::conformalVoronoiMesh::processorsAttached
 
     forAll(c1Procs, aPI)
     {
-        procsAttached.appendUniq(c1Procs[aPI]);
-        procsAttached.appendUniq(c2Procs[aPI]);
+        procsAttached.push_uniq(c1Procs[aPI]);
+        procsAttached.push_uniq(c2Procs[aPI]);
     }
 
     return List<label>(procsAttached);
diff --git a/applications/utilities/mesh/generation/foamyMesh/foamyQuadMesh/shortEdgeFilter2D.C b/applications/utilities/mesh/generation/foamyMesh/foamyQuadMesh/shortEdgeFilter2D.C
index b4804e5add..3141e0a4b3 100644
--- a/applications/utilities/mesh/generation/foamyMesh/foamyQuadMesh/shortEdgeFilter2D.C
+++ b/applications/utilities/mesh/generation/foamyMesh/foamyQuadMesh/shortEdgeFilter2D.C
@@ -46,8 +46,8 @@ void Foam::shortEdgeFilter2D::assignBoundaryPointRegions
         const edge& e = iter.key();
         const label regi = iter.val();
 
-        boundaryPointRegions[e.start()].appendUniq(regi);
-        boundaryPointRegions[e.end()].appendUniq(regi);
+        boundaryPointRegions[e.first()].push_uniq(regi);
+        boundaryPointRegions[e.second()].push_uniq(regi);
     }
 }
 
@@ -66,7 +66,7 @@ void Foam::shortEdgeFilter2D::updateEdgeRegionMap
     const edgeList& edges = surfMesh.edges();
     const labelList& meshPoints = surfMesh.meshPoints();
 
-    patchSizes.setSize(patchNames_.size(), 0);
+    patchSizes.resize_nocopy(patchNames_.size());
     patchSizes = 0;
 
     forAll(edges, edgeI)
@@ -78,15 +78,13 @@ void Foam::shortEdgeFilter2D::updateEdgeRegionMap
 
         const edge& e = edges[edgeI];
 
-        const label startI = meshPoints[e[0]];
-        const label endI = meshPoints[e[1]];
-
         label region = -1;
 
-        const DynamicList<label> startPtRegions =
-            boundaryPtRegions[surfPtToBoundaryPt[startI]];
-        const DynamicList<label> endPtRegions =
-            boundaryPtRegions[surfPtToBoundaryPt[endI]];
+        const DynamicList<label>& startPtRegions =
+            boundaryPtRegions[surfPtToBoundaryPt[meshPoints[e.first()]]];
+
+        const DynamicList<label>& endPtRegions =
+            boundaryPtRegions[surfPtToBoundaryPt[meshPoints[e.second()]]];
 
         if (startPtRegions.size() > 1 && endPtRegions.size() > 1)
         {
diff --git a/applications/utilities/mesh/manipulation/polyDualMesh/meshDualiser.C b/applications/utilities/mesh/manipulation/polyDualMesh/meshDualiser.C
index 5fcf5d2f89..384143a52d 100644
--- a/applications/utilities/mesh/manipulation/polyDualMesh/meshDualiser.C
+++ b/applications/utilities/mesh/manipulation/polyDualMesh/meshDualiser.C
@@ -518,7 +518,7 @@ void Foam::meshDualiser::createFacesAroundEdge
 
                 if (startDual != -1)
                 {
-                    verts.appendUniq(startDual);
+                    verts.push_uniq(startDual);
                 }
             }
             break;
diff --git a/src/OSspecific/MSwindows/fileMonitor/fileMonitor.C b/src/OSspecific/MSwindows/fileMonitor/fileMonitor.C
index 9d9a4865c7..4a8bbd2dd8 100644
--- a/src/OSspecific/MSwindows/fileMonitor/fileMonitor.C
+++ b/src/OSspecific/MSwindows/fileMonitor/fileMonitor.C
@@ -497,7 +497,7 @@ bool Foam::fileMonitor::removeWatch(const label watchFd)
             << watchFile_[watchFd] << endl;
     }
 
-    freeWatchFds_.appendUniq(watchFd);
+    freeWatchFds_.push_uniq(watchFd);
 
     return watcher_->removeWatch(watchFd);
 }
diff --git a/src/OSspecific/POSIX/fileMonitor/fileMonitor.C b/src/OSspecific/POSIX/fileMonitor/fileMonitor.C
index 110876a903..a9fe633fdb 100644
--- a/src/OSspecific/POSIX/fileMonitor/fileMonitor.C
+++ b/src/OSspecific/POSIX/fileMonitor/fileMonitor.C
@@ -493,7 +493,7 @@ bool Foam::fileMonitor::removeWatch(const label watchFd)
             << watchFile_[watchFd] << endl;
     }
 
-    freeWatchFds_.appendUniq(watchFd);
+    freeWatchFds_.push_uniq(watchFd);
 
     return watcher_->removeWatch(watchFd);
 }
diff --git a/src/OpenFOAM/containers/Buffers/CircularBuffer.H b/src/OpenFOAM/containers/Buffers/CircularBuffer.H
index fa0a893189..c5f0519bff 100644
--- a/src/OpenFOAM/containers/Buffers/CircularBuffer.H
+++ b/src/OpenFOAM/containers/Buffers/CircularBuffer.H
@@ -524,8 +524,8 @@ public:
         //FOAM_DEPRECATED_FOR(2022-10, "push_back()")
         void append(const UList<T>& list) { this->push_back(list); }
 
-        //- Append an element if not already in the buffer.
-        //FOAM_DEPRECATED_FOR(2022-10, "push_uniq()")
+        //- Same as push_uniq()
+        FOAM_DEPRECATED_STRICT(2022-10, "push_uniq()")
         label appendUniq(const T& val) { return this->push_uniq(val); }
 };
 
diff --git a/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H b/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
index 2850fb073a..691f233e27 100644
--- a/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
+++ b/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
@@ -443,8 +443,8 @@ public:
             this->push_back(std::move(list));
         }
 
-        //- Append an element if not already in the list.
-        //FOAM_DEPRECATED_FOR(2022-10, "push_uniq()")
+        //- Same as push_uniq()
+        FOAM_DEPRECATED_STRICT(2022-10, "push_uniq()")
         label appendUniq(const T& val) { return this->push_uniq(val); }
 };
 
diff --git a/src/OpenFOAM/containers/Lists/List/List.H b/src/OpenFOAM/containers/Lists/List/List.H
index ae846f3fd8..ec0283589c 100644
--- a/src/OpenFOAM/containers/Lists/List/List.H
+++ b/src/OpenFOAM/containers/Lists/List/List.H
@@ -395,8 +395,8 @@ public:
             this->push_back(list);
         }
 
-        //- Append an element if not already in the list.
-        //FOAM_DEPRECATED_FOR(2022-10, "push_uniq()")
+        //- Same as push_uniq()
+        FOAM_DEPRECATED_STRICT(2022-10, "push_uniq()")
         label appendUniq(const T& val) { return this->push_uniq(val); }
 
 
diff --git a/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C b/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
index a4fbe118b6..4c70358920 100644
--- a/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
+++ b/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
@@ -1065,14 +1065,9 @@ void Foam::ListOps::appendEqOp<T>::operator()
 {
     if (y.size())
     {
-        label len = x.size();
-        if (len)
+        if (x.size())
         {
-            x.resize(len + y.size());
-            for (const T& val : y)
-            {
-                x[len++] = val;
-            }
+            x.push_back(y);
         }
         else
         {
@@ -1095,11 +1090,7 @@ void Foam::ListOps::uniqueEqOp<T>::operator()
         {
             for (const T& val : y)
             {
-                // --> x.push_uniq(val)
-                if (!x.contains(val))
-                {
-                    x.push_back(val);
-                }
+                x.push_uniq(val);
             }
         }
         else
diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.C b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.C
index a31c38f3ab..9a39842a67 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.C
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.C
@@ -239,7 +239,7 @@ Foam::List<Foam::labelPair> Foam::mapDistributeBase::schedule
 
             for (const labelPair& connection : nbrData)
             {
-                allComms.appendUniq(connection);
+                allComms.push_uniq(connection);
             }
         }
     }
diff --git a/src/OpenFOAM/primitives/strings/lists/hashedWordList.H b/src/OpenFOAM/primitives/strings/lists/hashedWordList.H
index 7be6f41e0b..a9f63bfb17 100644
--- a/src/OpenFOAM/primitives/strings/lists/hashedWordList.H
+++ b/src/OpenFOAM/primitives/strings/lists/hashedWordList.H
@@ -184,16 +184,16 @@ public:
         //- Same as contains(), searches the hash.
         bool found(const word& val) const { return this->contains(val); }
 
-        //- Append an element if not already in the list.
+        //- Same as push_uniq()
         FOAM_DEPRECATED_FOR(2022-05, "push_uniq method")
         void append(const word& val) { this->push_uniq(val); }
 
-        //- Append an element if not already in the list.
+        //- Same as push_uniq()
         FOAM_DEPRECATED_FOR(2022-10, "push_uniq method")
         void push_back(const word& val) { this->push_uniq(val); }
 
-        //- Append an element if not already in the list.
-        //FOAM_DEPRECATED_FOR(2022-10, "push_uniq method")
+        //- Same as push_uniq()
+        FOAM_DEPRECATED_STRICT(2022-10, "push_uniq method")
         label appendUniq(const word& val) { return this->push_uniq(val); }
 };
 
diff --git a/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C b/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
index aa1e51e925..f4db96fdb8 100644
--- a/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
+++ b/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
@@ -212,7 +212,7 @@ Foam::wordList Foam::fvMeshDistribute::mergeWordList(const wordList& procNames)
         {
             for (const word& name : names)
             {
-                mergedNames.appendUniq(name);
+                mergedNames.push_uniq(name);
             }
         }
     }
diff --git a/src/dynamicMesh/polyTopoChange/polyTopoChange/combineFaces.C b/src/dynamicMesh/polyTopoChange/polyTopoChange/combineFaces.C
index 3a7c096bff..0233e32c5d 100644
--- a/src/dynamicMesh/polyTopoChange/polyTopoChange/combineFaces.C
+++ b/src/dynamicMesh/polyTopoChange/polyTopoChange/combineFaces.C
@@ -262,7 +262,7 @@ bool Foam::combineFaces::faceNeighboursValid
                 }
                 else
                 {
-                    neighbourFaces.appendUniq(nbrI);
+                    neighbourFaces.push_uniq(nbrI);
                 }
             }
 
diff --git a/src/dynamicMesh/polyTopoChange/polyTopoChange/hexRef8/hexRef8.C b/src/dynamicMesh/polyTopoChange/polyTopoChange/hexRef8/hexRef8.C
index 81bb134441..ec0107694e 100644
--- a/src/dynamicMesh/polyTopoChange/polyTopoChange/hexRef8/hexRef8.C
+++ b/src/dynamicMesh/polyTopoChange/polyTopoChange/hexRef8/hexRef8.C
@@ -1837,26 +1837,11 @@ bool Foam::hexRef8::matchHexShape
             {
                 // Add to pointFaces for any level+1 point (this might be
                 // a midpoint of a split face)
-                forAll(f, fp)
+                for (const label pointi : f)
                 {
-                    label pointi = f[fp];
                     if (pointLevel_[pointi] == cellLevel+1)
                     {
-                        auto iter = pointFaces.find(pointi);
-
-                        if (iter.good())
-                        {
-                            labelList& pFaces = iter.val();
-                            pFaces.appendUniq(facei);
-                        }
-                        else
-                        {
-                            pointFaces.insert
-                            (
-                                pointi,
-                                labelList(one{}, facei)
-                            );
-                        }
+                        pointFaces(pointi).push_uniq(facei);
                     }
                 }
             }
diff --git a/src/dynamicMesh/slidingInterface/enrichedPatch/enrichedPatchPointPoints.C b/src/dynamicMesh/slidingInterface/enrichedPatch/enrichedPatchPointPoints.C
index 3362ec1640..0768d14012 100644
--- a/src/dynamicMesh/slidingInterface/enrichedPatch/enrichedPatchPointPoints.C
+++ b/src/dynamicMesh/slidingInterface/enrichedPatch/enrichedPatchPointPoints.C
@@ -57,12 +57,10 @@ void Foam::enrichedPatch::calcPointPoints() const
             DynamicList<label>& curPp = pp[curFace[pointi]];
 
             // Do next label
-            const label next = curFace.nextLabel(pointi);
-            curPp.appendUniq(next);
+            curPp.push_uniq(curFace.nextLabel(pointi));
 
             // Do previous label
-            const label prev = curFace.prevLabel(pointi);
-            curPp.appendUniq(prev);
+            curPp.push_uniq(curFace.prevLabel(pointi));
         }
     }
 
diff --git a/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C b/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C
index 8783179386..b6b9bedb27 100644
--- a/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C
+++ b/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C
@@ -176,7 +176,7 @@ void Foam::CFCFaceToCellStencil::calcCellStencil
                         label nbrGlobali = globalNumbering().toGlobal(nbrFacei);
 
                         // Note:should use hashset?
-                        allGlobalFaces.appendUniq(nbrGlobali);
+                        allGlobalFaces.push_uniq(nbrGlobali);
                     }
                 }
             }
@@ -188,7 +188,7 @@ void Foam::CFCFaceToCellStencil::calcCellStencil
                 for (const label nbrGlobali : nbrGlobalFaces)
                 {
                     // Note:should use hashset?
-                    allGlobalFaces.appendUniq(nbrGlobali);
+                    allGlobalFaces.push_uniq(nbrGlobali);
                 }
             }
         }
diff --git a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
index fb84d4622b..572c6673a3 100644
--- a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
+++ b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
@@ -1967,16 +1967,8 @@ void Foam::snappyLayerDriver::getPatchDisplacement
 //                const label patchFacei = pFaces[pFacei];
 //                const label meshFacei = pp.addressing()[patchFacei];
 //                const label celli = mesh.faceOwner()[meshFacei];
-//                Map<labelList>::iterator faceFnd = cellToFaces.find(celli);
-//                if (faceFnd.good())
-//                {
-//                    labelList& faces = faceFnd();
-//                    faces.appendUniq(patchFacei);
-//                }
-//                else
-//                {
-//                    cellToFaces.insert(celli, labelList(one{}, patchFacei));
-//                }
+//
+//                cellToFaces(celli).push_uniq(patchFacei);
 //            }
 //
 //            forAllConstIters(cellToFaces, iter)
diff --git a/src/meshTools/cellDist/cellDistFuncs.C b/src/meshTools/cellDist/cellDistFuncs.C
index 29bb06a81b..301354bc60 100644
--- a/src/meshTools/cellDist/cellDistFuncs.C
+++ b/src/meshTools/cellDist/cellDistFuncs.C
@@ -107,7 +107,7 @@ void Foam::cellDistFuncs::getPointNeighbours
 
     for (const label nbr : faceNeighbours)
     {
-        neighbours.appendUniq(nbr);
+        neighbours.push_uniq(nbr);
     }
 
     // Add all point-only neighbours by linear searching in edge neighbours.
@@ -125,7 +125,7 @@ void Foam::cellDistFuncs::getPointNeighbours
         for (const label facei : pointNbs)
         {
             // Check for facei in edge-neighbours part of neighbours
-            neighbours.appendUniq(facei);
+            neighbours.push_uniq(facei);
         }
     }
 
diff --git a/src/sampling/meshToMesh/calcMethod/meshToMeshMethod/meshToMeshMethod.C b/src/sampling/meshToMesh/calcMethod/meshToMeshMethod/meshToMeshMethod.C
index 513ba5f1ff..f1cd0e78e5 100644
--- a/src/sampling/meshToMesh/calcMethod/meshToMeshMethod/meshToMeshMethod.C
+++ b/src/sampling/meshToMesh/calcMethod/meshToMeshMethod/meshToMeshMethod.C
@@ -166,9 +166,9 @@ void Foam::meshToMeshMethod::appendNbrCells
     // filter out cells already visited from cell neighbours
     for (const label nbrCelli : nbrCells)
     {
-        if (!visitedCells.found(nbrCelli))
+        if (!visitedCells.contains(nbrCelli))
         {
-            nbrCellIDs.appendUniq(nbrCelli);
+            nbrCellIDs.push_uniq(nbrCelli);
         }
     }
 }
diff --git a/src/thermophysicalModels/solidSpecie/reaction/Reactions/solidReaction/solidReaction.C b/src/thermophysicalModels/solidSpecie/reaction/Reactions/solidReaction/solidReaction.C
index 232c50eccf..6baafddc76 100644
--- a/src/thermophysicalModels/solidSpecie/reaction/Reactions/solidReaction/solidReaction.C
+++ b/src/thermophysicalModels/solidSpecie/reaction/Reactions/solidReaction/solidReaction.C
@@ -93,7 +93,7 @@ Foam::solidReaction<ReactionThermo>::solidReaction
     speciesTable allSpecies(species);
     for (const word& gasName : pyrolisisGases_)
     {
-        allSpecies.appendUniq(gasName);
+        allSpecies.push_uniq(gasName);
     }
     List<specieCoeffs> dummyLhs;
     List<specieCoeffs> dummyRhs;