Cat toilet training has its advantages if you can get your feline friend to give it a try. You won’t need to buy expensive litter, pads, or other waste-removal supplies. You can stop scooping the litter and taking it out to the trash. And perhaps best of all, cat waste odor is virtually eliminated. Once your cat is trained on your toilet at home, he’ll be able to use any toilet, anywhere, without a problem. That’s great news if you take your cat with you on vacation or move to a different house.
Well, an uncleaned litter box is the feline equivalent to that
The only real conflict is if your cat feels compelled to paw around in the water she's done her thing in it. I'm grateful that Misha never showed any such inclination, as I imagine that could get pretty disgusting. If you have this problem, you can try discouraging the post-toilet digging by praising your cat as soon as she's finished, flushing the toilet quickly to get rid of any lingering smell, and calling her away, thereby training her to get down immediately. You could also try feeding her just after she's used the toilet, as a distraction.
How to train your cat to use the toilet - The Washington Post
You’ve probably seen , and there, at the very least, you came across the idea of potty trained cats. The question is, can real-life kitties be trained to use the toilet? It turns out that the answer is “yes, but…”
Should You Teach Your Cat To Use The Toilet? - The Dodo