For marinade, stir together 3 Tbsp lemon juice, cooking oil, salt 1 /2 tsp black pepper, and garlic. Place chicken in a plastic zip top bag and pour over chicken. Marinate in the refrigerator for up to 24 hours.
In a saucepan, combine water, onion, sugar, butter, mustard, vinegar and 1 /2 tsp pepper. Bring to boiling, reduce heat. Simmer, uncovered, for 20 minutes. Stir in catsup, Worcestershire, 6 to 8 Tbsp lemon juice, and red pepper. Return to boiling; reduce heat. Simmer, uncovered until reduced to about 4 cups.
Meanwhile, drain and place chicken, bone side down, on grill rack over drip pan. Cover and grill for 50 to 60 minutes or until chicken is done. Brushing often with barbecue sauce the last 10 minutes of grilling.Servings: 4