I have seen pictures of cats that actually use the toilet, and seem to be very pleased doing that; but my cats have just used the litter box, when I had cats that were inside cats. We lived in the country, and often the cats just went in and outside, and we didn't need to even use a litter box because they would go to the door and meow to be let out.
I think that one thing that is VERY important to a cat is that their litterbox is clean and dry. I alwys kept the litterbox in the bathroom, and whenever I was in the room, or even noticed the cat using the litterbox; then I would clean it right away. I also scraped the litter around even when the cat had not used the box, and this allows the litter to dry out better. It also helps the bathroom to smell better when the litterbox is kept cleaned out, and the litter is changed often.
