In a medium bowl, combine salt, sugar, pepper, onion powder, garlic powder and water. Mix until the salt and sugar are dissolved in the water. Pour brine over pork. Allow pork to soak in brine for one week in the refrigerator.
Remove pork from brine, then discard brine. Rinse and pat dry the pork.
Preheat an outdoor smoker for 200 to 225 degrees F (95 to 110 degrees C).
In a medium bowl, mix together all ingredients. Evenly coat the pork with the rub and work it in with your fingers. Place a roasting rack in a drip pan and lay the meat on the rack. Smoke at 200 to 225 degrees F (95 to 110 degrees C) for12 hours, or until internal pork temperature reaches 160 degrees F (70 degrees C).