Liberally sprinkle the pork shoulder with the dry rub and gently pat to help the rub adhere. Tightly wrap the shoulder in plastic wrap and place in the refrigerator overnight.
In the morning unwrap the pork and place in the slow cooker. Add in the chicken broth, cover and cook on low for 8 hours. I don't recommend cooking on high. When cooking time is done remove pork and shred. Save some of the cooking liquid and stir it back into the shredded meat. I usually use anywhere from 1/2 to 1 cup of the cooking liquid. Stir in as much or as little bbq sauce to suit your tastes. Serve immediately.
Cooked meat can be stored in the refrigerator for up to 6 days.