When I smoke a pork butt I end up with a thick, hard, dry bark on my smoked pork butts. Normally, I'll pull out the biggest chunks during pulling. I am using a mustard on the meat then covered with rub. I spray the butts down with apple juice during the smoking process. I didn't really know anything was wrong until this weekend when we stopped at a local BBQ joint. The pulled pork was moist and delicious. I didn't care much for the rub cause it was way salty (i.e. chewing on a salt lick salty). What struck me was the bark was thin and moist. Excusing the saltiness of the rub, it was actually edible. So what am I doing wrong?