I was hesitant to try them until a friend of mine told me how much she liked them. There's no clumps glued to the bottom. The poop dries up and you swish the crystals around to air them and the urine dries up.

I have all my boxes using crystals at this point, and the only ones that go through crystals quickly are the 2 downstairs because I have lazy cats that would rather use just those two than go upstairs and use the other 8 all the time. They use the upstairs ones too, don't misunderstand, lol. I think also because Calloway stays downstairs most of the time, and he has diabetes and pees a lot, I go change the crystals in those two boxes about every 1 1/2 weeks. The upstairs boxes are lasting at least a month if not more, and the crystals don't get all saturated like the ones that Calloway uses.

Unless there's a major problems with the crystals, I'll never go back to clumping stuff.