Any item you place in doors will keep them open iirc.
Logically you could boil that down to the general elements of passable an impassable objects. An item (passable or impassable) cannot be placed upon or through and impassable object. A door is impassable, however once opened it passable mass is moved, opening a passable area. Thus if you could put something PASSABLE there, IE: a bolt of cloth, theoretically you can open it up permanently.
You used to be able to do it with just fishsteaks a bandage however I believe that the logical methodology of objects was altered, and that was fixed.
