1 (5-6 pound) pork butt. Sometimes called Boston or pork shoulder but DON'T buy the "picnic style" pork shoulder, that is designed to be sliced, not pulled off the bone, shredded.
1-1/2 tbsp sea salt
1-1/2 tbsp liquid smoke
1 Pierce pork all over with a carving fork.
2 Rub salt then liquid smoke over meat.
3 Place roast in a slow cooker.
4 Cover, and cook on Low for 16 hours, turning once during cooking time.
5 Remove meat from slow cooker, and shred, adding drippings as needed to moisten.
I know I've cooked this in far fewer hours than 16, I just play it by ear. The longer you cook it, the more it falls apart the way it is supposed to.
I usually serve over rice for the first meal and use the rest to make pulled pork sandwiches on onion buns with bbq sauce.