Preheat oven to 275° F.
Coat the ribs on both sides with the rub. Use about 1/4 cup per rack of ribs. (You will have some left over for another project.) Place them in a large roasting pan and pour the apple juice around them. Cover the pan with foil and place in the oven. Cook about 1-1/2 hours or until the meat is fork tender.
Remove the ribs from the pan. You can do this step up to a day in advance.
Heat a gas or charcoal grill to high heat. Brush the ribs with the barbecue sauce. If you like you can throw a few wood chips (like apple wood or mesquite) directly on the coals or the lava rocks. Place the ribs, meaty side down, on the grill and cook for about 3 minutes or until the sauce is bubbly and starting to caramelize. Turn them over and do the same to the other side. If you want more sauce and more caramelization, brush them lightly one more time and repeat the action.
Remove the ribs and cut them apart. Serve with extra sauce and lots of napkins.