Spread yellow mustard on a pork butt then covered it with a rub of paprika, onion powder, garlic powder, brown sugar, cumin, ancho chili powder, cayenne pepper and S&P. Wrapped in plastic wrap and sitting in the fridge overnight. Going in the crockpot around 8:00 tomorrow on a bed of thick sliced onions and a couple of cups of DDP (only because recommended here). Will remove around 5:00, drain the crockpot, pull the pork, add a bottle of Sweet Baby Ray's and cook for another hour (and add some cider vinegar if too sweet).