As a fan of Justin Wilson, I have used my share of oven bags. I don't believe they have a purpose in bbq though. When you wrap, the idea is to keep the foil or paper as tight against the meat as possible, so that it doesn't steam. The oven bag is designed to expand and allow the food to steam. Would you get a good pork butt, probably, but you can kiss any bark goodbye, and that is the best part of bbq.