If you like the chicken from the roadside chicken stands then you'll like this. I've been making this for about 15 years now and it's pretty darn good.
ROADSIDE CHICKEN
1 cup white vinegar
1/2 cup veg oil
1/4 cup worcestershire sauce
1 TBS Sea or Kosher salt
1 TBS white sugar
1 tsp garlic powder
1 tsp onion powder
1 tsp white pepper
1/2 tsp celery salt
Mix/shake till well dissolved. I put mine in a old worcestershire bottle with the shaker top. You can marrinate the chicken in the sauce for up to 2-8 hrs before cooking. If so discard marinade and make fresh for the cooking sauce. I apply the sauce every 5 min to both sides and turn every 5-10 min. Apply one final coating 5 min before removing from the grill. You can't put too much sauce on while grilling. It will build up a nice layer of flavors. I use the kettle but i think it would do well on the WSM (Larry used it) with no water pan and a high heat cook. I usally add one small piece of apple wood while grilling also. Hope you like it. Enjoy
EDIT: If you are going to marinate the chicken first, then leave the oil out for the marinade proccess. Make up a fresh batch for basting the chicken with the oil in the sauce.