I had one some years back and didn't have any problems with the cats not using it. In fact, they were fascinated with it at first. When it would start to do its thing, they would run into the room to watch it. You have to use the scoopable litter in them and I would use what is recommended. When I first started using it, I used what was recommended, but then wanted to save a few pennies and went with the cheap brands, which gummed up everything. Lesson learned.