COOK IT.
Follow the directions on your brine kit to make the brine. Refrigerate until cooled (40°F or less).
Remove the chickens from any packaging and pat dry with paper towels.
Place the chickens in large freezer bags, then add the chilled brine. Remove as much air from the bag(s) as possible and refrigerate for 24 hours.
When you're ready to grill, preheat your grill or smoker to 350°F.
Remove the chickens from the fridge and brine and pat dry with paper towels. Season on all sides with BBQ rub.
Truss the legs together with BBQ/butcher's twine before placing on your grill-safe rotisserie(s). Pro Tip: Be sure to wind the rotisserie completely beforehand.
Place the rotisserie(s) on the preheated grill. Release the rotisserie switch so the chicken starts to slowly spin.
Allow the chickens to cook, checking every 25 minutes and rewinding the rotisserie as needed to ensure even color and cook.
Check the chicken's internal temperature with a meat thermometer in the thickest part of the meat, usually the breast (but be careful to avoid touching the bone). Once the thermometer reads 160°F, remove them from the grill. This will be about 1 to 1.5 hours of cooking time.
Allow the chickens to rest for 10 minutes before carving and serving.