It's a suggestion not too unlike to "be on your best behavior." In this instance it is a recommendation to keep it clean and not to be vulgar, well too vulgar.
Grandma: "Now listen children. I need you to be on your bath behavior in church today. No one is to spit or call the priest a child-molesting pedo again!"
Louie: "Can I at least spit in the holy water, Grandma?"
Grandma: "If I don't see it happen, then it didn't happen."
(V) When you splash through a puddle and there is a ratchet hanging by the bus stop.
I was driving thru the hood and saw a stankin ratchet standing next to a puddle and I cleaned her up with a hood bath.
another term for "whatever" meaning joking or being silly.
Bihh, go bathe!
April 19th, give your Den a nice deep cleansing sponge bath. (Using a sponge is optional, you can use whatever you have on you that is handy, ie tongue etc).
Shocked by how filthy and dirty Den was, I decided to give him a sponge bath on National Give Den a Sponge Bath Day. A perfect day for a nice deep spring cleansing, get deep in all the cracks and crevices.
Whiskers is filthy. I'm going to put the cat in the bath.
In bath
A businessman and black beauty's owner in bath