You can soak them in Italian Island Dressing. A guy we know cooks for a small restaurant (they serve chicken breasts grilled and steak and baked potatoes and a house salad. period. They're open Thursday, Friday, and Saturday and they sell out of chicken every time.). He soaks them all day in the dressing in the fridge.
In the rotisserie we always put butter and seasonings inside before we tied it up and skewered it. Then we put a rub on the outside.