I had a guy once, older guy, probably in his 70s. He asked for a shower after the booking. I said sure, let me turn the water on for you (this was in my old flat and the shower was temperamental) and fetch you a fresh towel. He said oh that's okay I always bring my own towel.
I thought fair enough, maybe he's a bit of a germophobe. Left him in the bathroom. 10 minutes later he called out saying he couldn't turn the shower off. I went into the bathroom and he was towelling himself down with, I'm not kidding, Regina Blitz kitchen roll.
After he left I went back into the bathroom and he had kindly left me with about 4 miles of used Regina Blitz and an unflushed toilet. Cunt.