Washing your hands after relieving yourself in the men's restroom is quite pointless, for a reason not many think of.
Back in high school biology, one of our projects was to "swab" five random spots around the school building and transfer the results into specially-treated pitri dishes to see what would grow.
I had a working theory at the time that the boys' restrooms in the school were the nastiest places on Earth, so I conducted an experiment of my own. I had only five dishes to work with, and for various reasons, it was best to swab each dish with only a single sample. So I chose two spots in a classroom I knew was touched often by many hands. I figured it would be gross and would make a good "control group".
The other three samples were taken from three surfaces everyone touches in a restroom if they wash their hands: the faucets, the towel dispenser handle, and the door handle (only for bathrooms where there's a door, and where it's pulled open from inside). Sure, you touch the door handle whether you wash your hands or not (keep this in mind). We let the bacteria samples grow for a week, then looked at the results.
Oddly enough, the two control group samples were pretty dull; minimal growth, and as bacteria goes, this stuff didn't look too offensive. Sure, it all looks offensive when you know what it is, but it was very plain. Just one color, kind of powdery. The three bathroom samples were disgusting. Lots of colors. Lots of spots. Much more growth.
By far the most disgusting of the surfaces was the door handle. This demonstrated an interesting couple of points, set below in a handy reference for your friends, about washing your hands in a public restroom:
- Unless you've actually gotten your own bodily fluids and excretions on your hands, there's not really much reason to wash your hands anyway. Yes, your genitals are home to harmless bacteria (harmless to your genitals, anyway), but your minimal contact with them will not cause any harm.
- Every surface involved in trying to clean your hands is far dirtier than your hands are. The door handle has seen every person's hand who's used the bathroom. The towel dispenser (or air dryer) has been touched by every person who's touched the faucets. The faucets have been touched by every hand deemed worthy of washing, before they've been washed.
If you're worried about the cleanliness of your hands, they'll come out cleaner if you don't wash them in a public facility.