Preheat a grill or smoker to 375 degrees F. (If using wood, I love cherry or apple wood.)
Lop off about 1/4 inch from the top of a drumstick, and from the tip of the handle of the drumstick, using dry hands and a dry knife. (This way, you can stand them up straight, and it makes pulling the meat up easier.) About an inch up from end of the handle, where the bulb meets the handle, make a sharp cut that goes all the way around the handle (a 360-degree cut), making sure to cut through the skin, muscle and tendons. Push the meat up to the more bulbous end of the leg and remove the little bit of meat on the handle end. Repeat with the remaining drumsticks.
Place the rub in a small sheet pan or flat dish and roll each drumstick in the rub. Place the drumsticks directly on the grill and cook, rotating a couple times throughout, until the internal temperature registers 165 degrees F, 20 to 30 minutes.
Dunk each drumstick into the Glaze and stand up on the grill until the sauce is caramelized and set, another 10 to 12 minutes.
Honey Bourbon Glaze:
Combine in the bourbon, ketchup, vinegar, honey, mustard and brown sugar in a small saucepot and simmer for 10 minutes.