Well, first, strip them down naked and throw a bucket of Shiit/Piss/Puke or anything from the body on them, and them permanently damage their face by.... oh wait, this is what you DIDN'T want.

Well... fill their bathroom with shaving cream, use plastic wrap outside the door to build a barrier and just pump it full of the foam. Although you might want to get some kind of wholesale deal, it will take a lot.