I can confirm this as well. For one, it doesn't even work that well. You're still doing a lot of manual scraping and cleanup too. The thing also just scares the cat. And if you know anything about cats, they're very particular about their litter box, especially about privacy and a sense of "safety". A motor and loud sounds coming from their litter box at various times throughout the day is not generally something they will feel comfortable with and it's possible that they just won't even use it at all.