The microwave is fine for reheating BBQ-- the key word is "gently". Place a few servings in a dish, cover with wax paper, and microwave at 30% power for a minute at a time until warmed to your liking. Some meats, like brisket, benefit from a tablespoon or two per serving of broth or apple juice, or even water if it's all you have, to the dish while heating.