As I understand the term, a cat bath is pretty much synonymous with a whorebath. In that it basically involves a washcloth, soap, and a sink. Also, I believe it may be British slang.
"Dude! My, shower head was clogged, so I had to cat bath in the sink to de-funk my willie."
A bathtub bukakke from a bunch of irish guys.
"She told me her new favorite drink at the Pub is an Irish Cream Bath."
"That's not a drink, Steve."
When you are in the bathtub either bathing or showering when suddenly you spring a surprise chub shocking your mind and body in the weirdest but oddly pleasing way
I was just scrubbing my neck when I got a bath chub!
When one uses a public restroom to wash their genitalia when in expectation of sexual intercorse.
Bob needed to take a quick splash bath before seeing Jim
Using a fabric softener sheet to hide your stench when you don't have time for a shower.
Lindsay does so many Walks of Shame that she must be queen of the Bounce Bath.
When you're hittin it doggy and try to squeeze your nuts in her ass, but they keep jumping out like dogs in the bath.
You can only put your dogs in the bath if you have BB sized balls.