Why do I think that? Because washing your hands while wearing a hoodie if it has decently long sleeves is annoying, and I have to admit while I'm alone in a public restroom in my slightly over sized hoodie I feel the temptation to just walk out. Now I do wash my hands because I'm a good person but I know sure as hell someone is giving into the temptation. There are people who don't even wash their hands when wearing a short sleeve shirt! The bastards. There are people who don't even return a shopping cart when everyone can see them not return it. So what do you think happens when someone realizes, oh shit, I'm going to be walking around with wet cuffs? They walk out.
In fact you can have some fun with people. If you see someone in a hoodie walk out of a bathroom point out that their cuffs aren't wet. See how long it takes for them to realize they've been found out.