Memphis Dark Baste for Boston Butt

"I was divorced back in 1975,and my favorite brother in law,Mackie, left me.He took with him several fond memories including the best barbecue recipe in the world. He grew up near Memphis and made a special sauce which was coal black in color and he used this on Boston Butts.We would dig a pit and fill in the bottom with hickory,then sit down for an 18 hour barbecue.Gradually he would add charcoal to the fire to just barely keep the fire going.He could put his hand near the grill and count to ten.When he completed his work we had the best barbecue in the world.Does anyone know about this recipe. He claimed he was raised on it in Georgetown."