Mock Margarita Punch
["1 (12 oz.) can frozen lemonade, thawed", "1 (12 oz.) can frozen limeade, thawed", "1 c. powdered sugar", "6 c. crushed ice", "4 egg whites", "4 c. chilled club soda", "lime slices", "coarse salt"]
["In 4-quart non-metal container, combine lemonade and limeade concentrates, egg whites, powdered sugar and crushed ice; mix well.", "Cover; freeze, stirring occasionally. Remove from freezer 30 minutes before serving.", "Spoon 2 cups slush mixture into blender; add 1 cup club soda.", "Cover; blend until frothy."]
["frozen lemonade", "frozen limeade", "powdered sugar", "crushed ice", "egg whites", "club soda", "lime slices", "salt"]