toilet training??

I had Mozart trained before he got neutered. He did fine, and even remembered to use the potty potty when he got home. He actually looked RELIEVED to see the potty potty lol...

One advice if your going to try it;
Use a disposable aluminum roasting pan the size for your toilet. I'm NOT kidding. Use flushable litter, and then start with a LITTLE hole in the middle of it, and SLOWLY increase it's size, and don't freak out if the cat is SUPER interesting in the flushing process through that little hole. Mozart is still even fascinated about how the stuff goes bye bye and new water appears!

Oh, and NEVER get mad at them for going somewhere else. Mozart did that a couple of times so we learned his potty hours and put him in the bathroom. well a couple times he went on the floor in there, but eventually he got sick of us always putting him on the potty and telling him to go and staying there with him until he did, so he figured "well I might as well go by myself and get treats for doing it" :D

I'v had Phoenix for 3 years and he was totally litter trained. Then all of a sudden he stopped using the boxes. (I have 2 cats) I took him to the vet to see if he had any physical problems and he checked out just fine. The vet informed me it was probably a behavior problem. I answered all his questions about any changes in the household. There were none. He said.. "bad kitty" and gave me a few suggestions. None of them worked! I'v had Phoenix ever since he was a kitten. He was neutered at 5 months. Any ideas? Thanks, Buzzbee