Mess free?? No such thing! Mine says ewww when he has to poop but somes its after he's already done it.

Try putting blue food coloring in the toilet and tell them to turn the water green and then reward with one m&m !! It worked for my boy and my daughter!! Now poop is different from potty training it's a whole new territory so get potty down and then move on to the poop and only use pull ups at bed time or nap time

My sons 3 and we are just now potty training but lots of messes. Especially poop messes, my son is refusing to poop in the potty he’s still pooping in his underwear.

Good luck! My middle was bribable. But really had no interest!