1 (6- to 8-pound) Boston butt pork roast (bone-in or boneless)
1/4 cup water (or beer, apple juice, or a mixture)
Kosher salt (to taste)
Black pepper (freshly ground, to taste)
Optional: 1/8 to 1/4 teaspoon cayenne pepper
2 to 3 cups barbecue sauce
Put the pork shoulder in the slow cooker, cutting the roast to fit if necessary.
Add the water or other liquid and sprinkle the pork lightly with kosher salt, freshly ground black pepper, and cayenne pepper, if using.
Cover and cook on LOW for 7 to 9 hours.
Drain off the excess liquids, shred the meat with two forks, and discard any excess fat and bone.
Return the meat to the crockpot and pour about 1 cup of barbecue sauce over. Cover and cook another 1 to 2 hours.
Serve the shredded barbecued pork with extra barbecue sauce on the side.