I don't know how many others have tried this but the rave reviews from my last pulled pork have convinced me that re-adding the drippings - MINUS THE FAT - into the pulled pork is the way to go with pulled pork (and beef for that matter).
The simple method is to put a drip pan under the pork butts during the smoking phase (60% - 70% of the total cook time). When the meat is around 160 (and smoke absorption is finished), remove the drip pan and wrap up the butt(s) in tin foil for the final push up to the ending temperature (190 to 205 - whatever your preference).
Meanwhile, pour the drippings from the pan into a container and put in the fridge. By the time the pork is completed, the fat and bad parts will render to the top and can be easily scooped out and discarded. Then put the remaining sauce into a sauce pan and heat it up - get it hot but not boiling.
The juice is amazing - kind of like a burgundy broth and full of flavor with the spices from the rub.
If you are one to add a finishing sauce after the meat is pulled, you can add this sauce in there as well.