Place trimmed brisket into shallow roasting pan. Season with onion salt and celery salt. Soak in 3 oz. liquid smoke in refrigerator. Drain off liquid. Pour 5 oz. Worchestershire over meat, salt and pepper to taste. Cover pan with foil and bake for 5 hours at 275 degrees. Pour off liquid and trim off as much fat as possible. Pour 6 oz. Hickory Bar-B-Q sauce over brisket, cover with foil and bake for one more hour. Use drippings to pour over sliced brisket. Serves 8.