I have a cat that I did not get declawed. I think that's totally insane to do that. I also think the stupid litter boxes are toxic for them. They end up with all those chemicals on their paws, then they lick it off. I trained my cat off the litter box so he goes outside to do his business. He's the cleanest cat I've ever had!! Doesn't smell bad at all and is very healthy. I say get rid of the litter boxes, they're killing your cat!
What I did was replace the litter with dirt. Then put it outside, just outside the door. After a while he stopped using it and just did his business in the dirt outside.