She pees in it right before she poops, so it's clean besides that. She doesn't appear to be anxious, so I am going to try another litter/maybe a larger box, although hers is large already. I caught her trying to poop in the tub this time, put her in the litter box, and she dug about 1/3 of the litter out of the box before going. It was some intense digging. She didn't do that with peeing, though.