I found this recipe in a magazine. It really tenderizes the meat fast, I cooked a couple-pound pork loin that was still frozen for about 5-6 hours on a combination of low and high and it was almost over-tenderized.
2 pound pork tenderloin (or really any cut would work)
12 oz root beer
All you do is put the meat in there, and then dump in the root beer. After it cooked, I took the meat out of the root beer and I shredded it and mixed in bbq sauce and served it on hoagies or hamburger buns with coleslaw. An easy way to feed a crowd!