This is in actual law, so one can only wonder what prompted such thing to be enacted! It was enough of a problem that it was drafted as a bill and taken before the legislature ... where it was passed into law!
I'm not sure if it was a husband, wife, or child that insisted on letting the donkey sleep in a bathtub. In my example, I'm supposing it was the husband, and I imagine the conversation going something like this:
Wife: "I'm tired of cleaning donkey poop out of the bathtub everyday before I give the kids a bath! I forbid you to let that stupid donkey sleep in the bathtub one more night!"
Husband: "I can let the donkey sleep in the bathtub if I want, woman .... there ain't no law against it!"