As for the doorstop, if you are in a hostel, often even the private rooms do not lock... I met a few female travellers who were concerned about rape, and I met one who was sexually assaulted in her room. So I can see the merit to the doorstop too. But most of those seem like they would make travel more of a hassle.
Added at: 11:09
I did not ask how she cleaned it, I just teased her. I am a terrible friend.