Build a fire in the barbecue using the hardwood. It is permissible to start the fire with charcoal--just don't cook over it unless it is natural chunks of mesquite or oak charcoal, never briquettes. When the wood has burned to coals, spread them apart and place a metal drip pan, half-filled with water, in the center of the fire. Place the marinated pork on the grill, directly over the pan, and as far from the fire as possible. Next, either use the barbecue cover to cover the meat, leaving a small vent for fresh air, or make a tent with aluminum foil to cover the meat and keep in smoke.