Rub you add the night before or day of, load the meat and smoke. You don't open the door till the therm says it is time to test for doneness. Basting, you are opening the door at predetermined intervals. Every time you open the smoker door you are adding 20-30 minutes more cooking time. Basting puts moisture on the surface that causes evaporative cooling adding more additional cook time. Basting inhibits Bark formation and the constantly wet surface can attract undesireable strong smoke flavors. Repeated basting can add some additional flavor but marinades, brines and injection or a Finishing Sauce do a better job. If basting is something that you wish to try, for the least negative impact, basting once or twice the last hour of the smoke is, IMO the better choice. You want to Enhance the meat. Too many additions of anything can take you from say, " Smokey Pulled Pork " to " Smokey, Cinnamon, Apple, Maple, Whiskey, Garlic, Pulled Mystery Meat. "...JJ