I’d like to point out that expecting your cat to urinate/defecate in a human toilet is untenable if you have: A) Kittens; B) A cat with any sort of intestinal ailment; C) A cat with any sort of back, leg, or hip injury; D) A geriatric cat.
This is a cute trick for a young, healthy animal but just remember, if you make it difficult for them to get to where they need to go, they’re going to go where it’s more convenient (the floor) instead. And it’s going to be your fault, not theirs.