Light one side of grill, heating to 400 - 475 degrees (medium high to high) heat; leave other side unlit, placing disposable baking pan under grill grate. Stir together salt and next 5 ingredients; sprinkle mixture inside cavity and on outside of each chicken.
Reserve just 3/4 cup ginger ale from each can to put toward the 2 cups needed in the glaze. Place chickens upright onto each can, fitting can into cavity. Pull legs forward to form a tripod.
Pour water to a depth of 1 inch into disposable pan. Place chickens upright on unlit side of grill above pan. Grill, covered with grill lid, - rotating chickens occasionally, 1 hour 20 minutes to 1 hour 30 minutes or until golden and a meat thermometer, inserted in thickest portion, registers 165 degrees. Let stand 10 minutes. Remove chicken from cans, and carve. Serve with Ginger Glaze.
To make the glaze, stir 2 cups ginger ale or ginger beer, 2 tbsp. light brown sugar, 2 tsp. fresh grated ginger and 1/8 tsp. ground red pepper together in a small saucepan. Bring to a boil over high heat; reduce heat to medium, and cook (stirring occasionally)15-20 minutes or until reduced to about 1/4 cup.