P.M.
I think it's reasonable to allow him to back off until he's ready for the ongoing responsibility. I'd give him messages like, "You know, I was so happy when we didn't have to keep changing your diapers and cleaning you up. And I'm sure you will want to be potty trained just as soon as you realize how much quicker and easier it is to use the potty instead of getting changed over and over. Let me know next time you want to try the potty, okay?"
And let it go. It will affirm your confidence in your son's native wisdom about what he can handle. It will affirm your dedication to giving him control of this important function. And it will affirm your cheerful support of his growing independence. I'll bet once he gets all of that from you, it won't be long before he goes back to using the potty.
It will be less work for you, less stress for you both. And when kids are ready both emotionally and physically for this developmental step, bribes are not needed, just smiles and congratulations.