I understand that it can be disgusting for some, but checking cats' toilets regularly helps to detect health problems early. That's why it's better for them to defecate in the litter box instead of in a place where we can't check.

Does this actually work? How to keep the stink down … cause cats don’t flush also?

You'd have to setup an automatic flush 4 times a day, or setup a motion detect camera that tells you when the cat is doing it's business. It could work but knowing cats since they are basically still wild animals and can't be trained like dogs, it would probably get spooked if it flushes on its own or some other reason and then ud find their business in the corner somewhere. You'd get more success with dogs because my friend did this and he made the flush handle extend right outside the room so my roommate flushed for the dog right after the dog was done. After 8 hours at work or sometimes longer my friend would come home and find the dog used it and flushed it. It never failed. Supposedly he trained it young and my friend was also a plumber. Since my friend worked long hours and really wanted a dog. He said that solution worked. Now try training a cat to do that..