Check each chicken drumstick and pull the skin smooth over the meat. Cut away the excess skin.
Brine
Add to a pot the salt, brown sugar, and 2 cups of water. Warm over low heat until all the ingredients are dissolved.
Add the warm liquid to a large bowl then add the ice and cold water, stir to combine then add the prepared chicken legs. Leave to brine for 2 hours.
To Cook
Preheat the smoker, such as a Gateway Drum Smoker, to 325 degrees F (163 degrees C).
Remove the chicken from the brine and pat dry with a paper towel. Season both sides generously with your rub.
Place the chicken evenly with space for airflow on the preheated smoker. Close the lid and leave for 30 minutes.
After the first 30 minutes, turn the chicken over and cook for an additional 30 minutes.
Take the barbecue sauce and slowly heat it, the sauce should be a nice coating thickness. If too thick add some water or apple juice to thin it out. The sauce should be warm but still cool enough to touch.
Remove the chicken drumsticks off the smoker and completely dip them in the BBQ sauce to create an even glaze all over. Return to the smoker and cook until the glaze is set, about 5 minutes. Serve straight away.