R.R.
A sticker chart and a sticker each time with something special after 10 successful days of poops in the potty. It could be something inexpensive like a new coloring book, a big bottle of bubbles, a bag of Army men from the dollar store, etc. If you keep taking him to Walmart he may not get trained for years...
2 Skittles or M&M's, that's just 2 individual M&M's, not 2 bags ; )
High~fives. Seriously, my little guy is 28 months, pooping on the potty more regularly now, but stickers worked about 5 days, a Dum Dum pop about 3, and now he just wants the high-fives, so I'm getting off cheap!! (And something I read a few nights ago said that we shouldn't reward them with "things", but praise and a certificate to put on the wall.)