I tried some new litter - the pine pellet kind. I didn't just immediately switch, but did the slow thing a little of the pine pellets with plenty of their usual litter, then more pine pellets and less litter until it was all pine pellets. This was over maybe a two week time period. One cat was fine with it, he used it with no problems. But the other two hated it. One would not cover her business and one started using the bathroom on the rug. Should I just give up on using the pine pellets? It worked great at covering the smell, but if they aren't going to use it, well that's a whole other problem. Has anyone here ever made a major switch with their cat litters? If so did it work and how did you do it?