Cut the pork belly into 1-inch (2 1/2cm) cubes. Spray the pork belly with the duck fat spray and sprinkle all sides evenly with the Blues Hog seasoning.
Spray the wire cooling rack with duck fat spray. Place the pork belly cubes fat side-up on the rack, leaving a small space between each cube for even cooking.
Preheat your smoker to 275 degrees F (135 degrees C) with lump charcoal and your favorite fruit or nut tree wood.
Transfer the wire rack to the smoker and cook for 2 hours.
After 2 hours, spritz the cubes with apple juice. Continue to cook the pork until it reaches an internal temperature of 165 degrees F (75 degrees C).
Transfer the pork to an aluminum pan. Top the pork with the butter slices, then sprinkle with brown sugar and honey. Cover the pan with aluminum foil and return to the smoker.
Continue to cook the pork until it reaches an internal temperature of 200 degrees F (95 degrees C), about 1 1/2 hours.
Using tongs, transfer the pork to a new aluminum pan. Add the BBQ sauce and toss gently to coat. Return the pork to the smoker and cook, uncovered, for 5 to 10 minutes to allow the sauce to set. Serve immediately.