Both cats have access to all the litterboxes, but I've got three litterboxes around for Mowgli to choose from. I use the Tidy Cats Crystals - which, near as I can tell, doesn't have a scent. It just absorbs the pee (no more pee biscuits!) and dries out the poop really fast.

Hmmm... I didn't think about a UTI, though Mowg doesn't seem to be in any pain when he goes. Still, I guess I can try to figure out a way to get a sample and get it checked out.