Pulled pork for large group

Every Christmas I have to make a meal for my employees which is usually in the 35-40 range. I have made pulled pork twice. I figure about 3/4-1 pound of meat per person and I usually buy whole pork loins. I use the electric roaster. This will sound strange but I pour either root beer, Dr. Pepper or a cola over the meat...any generic brand will work. A two liter bottle usually does the trick. Add sliced onions and garlic to taste and cook it at about 185-200 until the meat is fork tender. Shred the meat and leave enough of the remaining soda to make the meat juicy but not swimming. Then I add about 2-3 bottles of BBQ sauce...any kind that you want. I tend to favor Famous Dave's. Since Christmas time is so busy I usually make this mid-November and freeze it. I have had many requests for the recipe and people are usually very surprised as to how it was made.