With my terra cotta smoker, powered by a 1000W hot-plate, I could never get pork butt to pull adequately - even if given 14 hours in the smoker! So, I thought I would take a cue from the technique of pastrami making. Pastrami is brisket (or navel), brined, soaked in water to remove excess salt, rubbed, smoked and steamed or pressure steamed. I gave a rather small, rubbed pork butt 7 hours on the smoker, The meat was pretty much cooked, but not pullable. I placed it on a rack in the pressure cooker with water coming up to below the bottom surface of the rack, and pressure-steamed it for 35 minutes.
The result was very juicy and tender pork, but some of the smoke flavor and bark were lost in the steaming process. Until I get a better hot-plate, this is the best I can do with what I've got.
Here is the recipe for the South Carolina style of sauce I used:
1/2 cup yellow mustard
1/2 cup white vinegar
4 Tbl white sugar
2 Tbl dark brown sugar
1/2 Tsp ground cayenne pepper
1 Tsp Tabasco sauce
salt and black pepper to taste
Place all ingredients into a non-reactive sauce pan, bring the contents of the pan to a furious boil, then cut off the heat.