Preheat the smoker to 250°. Place a drip pan filled with water under the grill grates.
Rub: Combine all of the ingredients and set them aside.
Spritzer: Add the apple juice, cider, and water to a spray bottle and shake. Set aside.
Rub the mustard on every side of the pork shoulder, creating a thin layer.
Next, generously season the pork shoulder on all sides with the rub.
Add the pork shoulder to the smoker over the drip pan filled with water and smoke for 3 hours.
Next, spray the pork shoulder with 15-20 sprays of the spritzer. Repeat this process for the next 3 hours every hour with the same amount of spritzes.
Once the pork reaches an internal temperature of between 165° and 170° or the top part of the fat on the bark has split, about 6-7 hours, remove the pork from the smoker.
Place the pork shoulder on a large sheet of double foil, generously spritz it, and wrap it extremely tight by folding over and covering up the pork shoulder.
Place the pork shoulder back on the smoker, bone side up, and cook until it reaches an internal temperature of 200° to 205°, about 2-4 hours.
Remove the pork shoulder from the smoker and rest in the foil for 30-60 minutes before removing the bone, and large chunks of fat, and pull it using forks, cloves, or tongs.
Serve pork shoulder with BBQ sauce on the side or as a sandwich.
