In a small bowl combine the water, Worcestershire sauce, vinegar, boillon granules, chili powder, mustard, red pepper, and garlic. Reserve 1/2 cup of mixture for the barbecue sauce. Trim any excess fat from the brisket. If necessary, cut the brisket to fit into a 3-1/2 or 4-quart crockery cooker.
Place brisket in crockery cooker. Pour the remaining Worcestershire sauce mixture over meat. Cover and cook brisket on low-heat setting for 10 to 12 hours or on high-heat setting for 4 to 5 hours.
For sauce, in a small saucepan combine the reserved sauce mixture, catsup, brown sugar, and cornstarch. Cook mixture over medium-high heat until thickened and bubbly. Cook and stir for 2 minutes more. To serve, remove meat from cooker; discard cooking liquid. Thinly slice meat diagonally across grain. Serve meat on toasted rolls. Pass sauce. Makes 8 servings.