Heat the smoker to 300 F.

In a small bowl, mix salt, pepper and brown sugar together.

Slather the pork shoulder with Dijon mustard, and then coat it with the rub, pressing it into the meat.

Place the pork shoulder on the grate of the smoker, and cook it for four hours. Every half hour, add a small amount of dry smoking wood. Every hour, open the smoker and quickly spray or mop the pork with apple cider vinegar.

After four hours, wrap the pork shoulder with two layers of heavy aluminum foil, put it back in the smoker and cook it for two more hours, or until the internal temperature reaches 195-200 F.

Remove the pork shoulder from the smoker, but let it rest in the foil for 30 minutes to an hour.

Remove the foil, shred it with forks and serve immediately.