I'm making a model of curved tube which have some self-intersections and wondering how to clean inner mesh in this area. Inersect(Knife) tool with Self Intersect Source highlights the outer vertexes but they are non-closed so still need some work. Maybe there is some semi-automatic way to clean it and leave only the outer shell?
The reason it doesn't cut clean is because this kind of curved tube has self-reverting faces in the corners :
You can fix it by using the knife, adding vertices and merging the closest vertices in those areas until you get this kind of result :
Then you should be able to select the self-intersected part of the tube with Ctrl+L :
I don't think there's any automated way to do this.