Gross! Also… a substantial portion of the granules get flushed down the bathroom. I haven’t researched those specifically… but I am able to’t imagine that it's excellent to your plumbing. The granules seem to be plastic. Probably they biodegrade? Idk.. not my fav. We're searching in to other units. It https://socialdosa.com/story10107065/a-review-of-robotic-pet-cleaning