I was just a kid, and in those days kids went barefoot all summer and then got new shoes for school. Summer was so hot that we didn't bother to take a bath until we were going to town.
So I'm sitting around, pretty much a blank mind, with one foot across my knee, when I noticed that the dust had mixed with sweat and dried on my ankle. It was really hard. I bet I could sand that stuff. So I got some sandpaper and sanded it. After a while it occurred to me that if I ever got through the dirt it was going to hurt, so I stopped. Then I had a flash: I could TAKE A BATH! Water would just turn that mud into liquid and it would all flow off. Nobody else was home, so I didn't have to think of an excuse or nuthin. I could take a bath just for a scientific experiment. Gee, did I ever feel smart!
Surprise, surprise! At first glance, I thought this question was asked by Unapologetically Trashy, but it wasn't. I'll say what I would've told him, that I've done this as often as I've worn trash bags, which is exactly zero times.