In a small mixing bowl whisk together salt, pepper, brown sugar, paprika, garlic powder, and cayenne pepper.
Place pork shoulder in a baking dish and rub entire roast with dry rub mixture, pressing mixture over the roast. Cover roast with plastic wrap and allow to rest in the refrigerator at least 2 hours, or overnight.
In a medium mixing bowl combine apple juice, apple cider vinegar, Worcestershire and liquid smoke.
Cover slow cooker and cook on low heat 8 - 10 hours.
Remove roast from slow cooker and shred (leave broth in slow cooker). Return shredded pork to slow cooker (in broth) and allow to cook 10 - 20 more minutes.
Strain most of the broth from pork (I leave about 1/2 cup), pour in barbecue sauce and toss.
Serve in buns with coleslaw if desired.
I like to serve with this coleslaw HERE. I like to add some blue cheese crumbles to it as well it pairs deliciously with the pork.
Serve with fresh bakery buns for best results. Skip those down the bread isle.