This might be wrong to post, but it sure works..
I use this recipe for a mop sauce when smoking a boston butt.
2 cups cider vinegar, 1 onion, 4 jalapenos,1 tbls course salt,1 tbls brown sugar,1 tsp black pepper,and 1 tsp red hot pepper flake.
The part that is wrong is that I use the oven for the last 2 hours. I usually have half the mop sauce left over, so I tried putting the butt in an oven bake bag(like for turkeys)with the left over sauce in the oven at 250 for the last 2 hours. Man I have never had such a soft and moist butt like this! Sorry if it breaks the rules but it was great!!