Used Worlds Best Clumping expensive but worth it. They dont bur bit when they weed it was like removing a brick. They pee for England. I got caught short and bought the sainsburys own brand which we all love. They are finally burying! Its the exact same as white Catsan but very cheap. The only thing is a can hardly see any wee now. And i can get a whiff of wee outside near my plant pots which i put down to the strays i feed. Could mine suddenly have started going outside?