We use a clumping Liter called simply fresh, it is unscented. The problem is that our female cat pees at and down edges of her liter box so it is a struggle to get her pee out. I tried arm and hammer slide but did not like it and it did not work. I also tried oiling the sides of the liter pan. That worked great but only for a few days. I am not sure if I should get a new liter box so the sides of it are more smooth or if I ,need a thin metal scooper? Maybe different liter? Did anyone have this problem with their cats pee sticking to the box?