Prepare the brine according to instructions. Brine thighs for 2 hours.
Remove the chicken from the brine solution, and blot dry with paper towels. Set them, skin side up, onto a clean plate or small baking dish. Refrigerate uncovered for 2 hours.
Preheat your smoker or grill to 250 degrees F. Use your choice of hardwood (smoker or charcoal grill) or wood pellets for pellet smoker.
Trim the chicken thigh skin into a square patch covering the meat, keeping one side attached. Remove any excess fat around the edges.
Season both sides and under the skin of each thigh with BBQ rub.
Place the thighs on the grill grate, skin side up. Close the lid, and cook them until they reach an internal temperature of 165, about 1-1 1/2 hours.
Remove your smoked chicken thighs from the grill and set them onto a heat-safe wire rack or clean cutting board. Brush with BBQ sauce.
Remove the chicken from the grill, and place them on a clean cutting board or platter. Let them rest for 10-15 minutes, and serve.
Place the thighs back on the grill. Close the lid, and and cook until they reach an internal temperature of 180-185 degrees F. For fall off the bone thighs, cook until they reach 195 degrees.
Once cooked, place the thighs on a serving platter, and let them rest for 5-10 minutes. Serve and enjoy!
Store leftovers in an airtight container in the refrigerator for 3-4 days. Freeze for up to 8 weeks. Rewarm in a 325-degree oven until they reach an internal temperature 165 degrees F.