I was thinking more of this: The Clapper Crapper
"Uranus Crapper invented the first pay toilet in 1904. The previous versions of the toilet were free to anyone who knew the secret code to unlock the lavatory door. By slapping one's hands together one could unlock the toilet and this became known in ballparks and bus stations around the country as the Clapper Crapper."
Well Golly, learn something new every day! :)