Preheat a large skillet with cooking spray to medium-high heat.
Generously coat the pork roast with the barbecue rub. Place in the hot skillet and sear on all sides - just enough to give it a bit of color.
Place the roast into the slow cooker. Combine the cola and barbecue sauce and pour it over the roast.
Cook on LOW for 6-8 hours or until the pork shreds apart easily.
Before serving drain off some of the liquid in the slow cooker and add additional barbecue sauce if you'd like the pork more saucy.
Serve warm on buns, topped with dill pickles and a side of coleslaw.
