1) Put the chicken in a non-reactive bowl. Combine 500ml of barbecue sauce, the seasoning rub and the vinegar, and pour it over the chicken. Cover and marinate the chicken in the refrigerator for at least 4 hours, preferably overnight.
2) Preheat the oven or smoker to 107C.
3) Remove the chicken and shake off the excess marinade. If cooking in an oven, place on a rack over a pan to catch the drippings. If cooking in a smoker, place directly on a rack. Use your favourite wood. Cook until the internal temperature, using an instant-read thermometer, registers 74C, about 1 1/2 to 2 hours.
4) Remove the chicken from the rack and place it in an aluminium tin. Brush with the reserved 125ml of barbecue sauce, cover with aluminium, and place back in the oven or smoker for half an hour. Remove the chicken from the pan and finish off in a barbecue. Using a medium to hot flame, barbecue until the outer skin is crisp and marked (a few minutes should do it).
Serve immediately. You may also place the chicken in a clean tin and cover with aluminium to keep warm until serving.
Cook's tip 1: Before adding your wood, make sure the cooking temperature has been achieved. Add the meat, then the wood. This will stop the meat looking too dark.
Cook's tip 2: For a sweeter taste, add 60ml of apple juice to your marinade. Adding apple juice to the barbecue sauce while barbecuing will give it a nice glaze, too.