Clean up intersecting geometry iam repairing a model that has intersecting geometry. It is a really dense mesh that was conected via boolean. So it is firmly connected but in a wrong way and i have no way to erase this zero thick wall without selecting it manualy, which is in that dense mesh almost impossible. Is there a way to isolate this kind of geometry and delete it?
If the mesh is watertight but has areas with zero thickness then these areas are non-manifold. In Blender 2.80 you can select them using Select > Select All by Trait > Non Manifold.



For 2.79 and earlier take a look at this answer by gandalf3.