Pour liquid smoke over meat and sprinkle both sides generously with the three salts. Wrap in foil and refrigerate overnight. Next morning, uncover and sprinkle with salt and pepper plus Worcestershire sauce. Do not drain.

Cover securely with foil and place in pan. Bake 5 hours at 250 degrees, then open foil and add barbecue sauce. Reseal and bake 1 more hour. Slice across the grain. Serve with juices. Serves 12 (4-pound brisket).