a tip that might help
We've been toilet traing our cat since August. We had mishaps along the way. We used city kitty which works fairly well but we found it works best to go much much slower and have a lot of patience. Toward the end when there was no litter left he seemed a bit confused as to where to go. Peeing was not a problem, but pooping was. We had to back up a couple times with City Kitty and each time, this fixed it.
With City Kitty we didn't used the perferated cut spots, instead we cut only about 1/4" away each week making the hole just a little bigger, and as I said, we did back up a couple times when needed. When we got to the last ringe, we slowly stopped putting litter in it as the directions said then eventually removed the ring. Seymore would let me know when he needed to poo by meowing loudly in the bathroom, but didn't seem to understand that he should use the toilet. So I took a palm full of litter and sprinkled it on the seat, he took one whiff, turned around and did his business in the toilet just like that. Apparently he just needed the litter smell to know that's where he needs to go.
So we put the ring back, and cut the ring back until there is a just small lip that is completely under the toilet seat. The nice thing about this is you can still add litter to it so he can smell it. We now sprinkle a little litter in the ring lip about once per week. This has been working great. He now uses the toilet with the citty kitty with small amount of litter, and two weeks ago, has started using the other toilet without the city kitty or litter. Sometimes to reinforce, if he's in the no city kitty bathroom with me, I'll sprinkle a little litter on the seat and set him up there. Works everytime. Especially if he just ate. Another tip, keep cat food dish in bathroom by the toilet as they tend to go right after eating. You can also feed him at intervals and stay busy in bathroom while he's eating, then keep your eye on him and if he's sniffing around, put him on the toilet.
It takes a lot of patience, but worth it. The first time I saw a cat use the toilet for waste was 30 years ago. I was brushing my teeth at my grandmas when her cat jumped on the toilet and started to pee. I went running out to the kitchen to tell my grandma and she said she already knew. I asked how she taught him that and she said she didn't, he just figured it out. I thought it was amazing.
Cats are smart, they learn by observing. They can learn to open doors, and push buttons to open the cd tray just for fun, and they can learn to use the toilet too. Good luck, and remember patience...