At a Loss...

I am STILL having issues with Sam's potty training. He doesn't wipe or clean himself and I've tried what I think is everything without success. It is a DAILY battle. Every night when we brush our teeth and change in to jammies I make him show me his doopy crack. It is always dirty and I have to make him wipe and clean himself. I've tried being understanding, patient, furious, shaming... you name it. I thought (hoped) it would eventually work itself out but it hasn't. Last night I went to tuck him in and he had poo smeared on his sheet. Disgusting. I lost it.

Trying to do searches and check websites for advice directs me to sites that are intended for help with a new 2-3 yr old. I've been going through this almost 3 yrs!

Anyone (mistress??) have words of wisdom?