In a small bowl, mix first 8 ingredients, through pepper. Pat pork dry and rub spice mixture all over. Spread onion and garlic on the bottom of a slow cooker and place pork on top. In small bowl, stir together barbecue sauce, cider, chicken broth, honey and Worcestershire sauce; pour over pork. Cover and cook on low heat until meat shreds easily, about 8 hours.
Remove pork from cooker; set aside. With a spoon, skim off as much fat as possible from liquid in cooker. Remove 1 cup of liquid; reserve. Increase slow cooker heat to high. Using 2 forks, shred pork and return to cooker. Cover cooker and cook on high 1 hour longer.
Preheat reserved liquid. Serve pulled pork on buns with your favorite homemade or store-bought coleslaw, passing sauce.