4. To Finish on the Grill: Light one half chimney full of charcoal. When all the charcoal is lit and covered with gray ash, pour out and arrange the coals on one side of the charcoal grate. Set cooking grate in place, cover grill and allow to preheat for 5 minutes. Alternatively, set half the burners on a gas grill to the medium-high heat, cover, and preheat for 10 minutes. Clean and oil the grilling grate.
5. Remove pork from bag and carefully blot dry with paper towels. (The liquid from the bag can be added to your favorite barbecue sauce and simmered down to provide extra flavor.) Rub the reserved spice rub into the surface of the pork. Place the pork on the cooler side of the grill. Add some hardwood chunks to the hotter side of the grill. Cover and allow pork to smoke, adjusting vents to maintain a temperature between 275 and 300°F and replenishing the wood chunks twice during cooking. Smoke until a deep, dark bark is formed, about 1 1/2 hours.
7. Transfer the pork to a large bowl or cutting board. Using a couple of forks, shred the meat into bite-sized pieces (or if you cooked at 145°F, use a knife to slice the pork). Season pulled pork to taste with salt and serve immediately, passing your favorite barbecue sauce at the table.