I used to manage a family restaraunt and we did something similiar. We put the potatos in a big pan of water (we didn't score them) and put them on the grill to cook. When they were fork ready. we took them off the grill and drained the water off and let them set until they were cool enough to handle. We would use a plastic knife and the skin would just peel right off. We would do about 15 pounds at a time and have them done in no time at all.