This is a great invention. It's so nice not having to clean a gross litter box. The plastic pellets do still tread, but I'm not grossed out by them because the machine does an incredible job cleaning. The SaniSolution lasts a long time. After the machine runs, the whole bathroom smells amazingly clean, cleaner than when I do the whole cleaning routine. The company also has great customer service. I won my unit by entering a video contest they sponsored.