It’s entirely possible that the waitress does that, but it’s definitely not the norm. If you can get yourself into the pit room you’ll see a big pot of sauce and a man with a big fork. He takes the cooked chickens off the pit and immediately dips them in the white sauce. Then they go to the kitchen. That’s the main function of the white sauce. I don’t care much for the sauce on it’s own but those chickens are great.
As you all probably know BBG has had great success at the Memphis in May World BBQ Championship but they definitely don’t use any white sauce on their legendary pork shoulders there. Well a couple years ago some other team included a cup of white sauce in their shoulder presentation. The general consensus was that they were thinking they’d fool a few misguided judges into thinking their entry belonged to Big Bob’s.