It sounds to me like your kitten has simply developed a rather annoying habit - we all have bad habits, and animals are no exception. The important thing is figuring out why he does it, and working on getting him to stop. Is his litter box kept clean at all times? Cats are very, very clean animals, and if they feel that their usual area is not up to scratch (no pun intended), they will go somewhere else. I take it that you aren't in a position to allow him to go outside to do his business? In that case, maybe try removing poo and clumped urine out of his box as soon as it happens, and remember to top the litter up each time. In regards to the urinating in the bath: I don't agree with the methods of "punishment" that include rubbing the animals face in their mess to "teach" them not to do it. A spray bottle with some water will do the trick. Every time you see him in the bath, about to pee, or in the act of peeing, spray his body or the top of his head with the water bottle. Trust me, he will HATE it and will quickly learn to go elsewhere. It's important, though, that you place him in the litter box afterwards so that he can pee, and get used to going there. I have even had to help my kittens "dig" in the litter, to get them used to it. Also keep in mind that if you are cleaning your bath with bleach, this will attract your cat, as there is a component in bleach that smells like cats urine (to them), so he may be confused into thinking it's a normal place to go. Good luck!