The crossword solution for the term 'Listerine Rival' is SCOPE. SCOPE is a brand of mouthwash manufactured by Procter & Gamble. It was introduced in the United States in 1967 and has since become one of the most popular brands of mouthwash. It is marketed as an alternative to Listerine, which has been the leading brand of mouthwash since its introduction in 1895. SCOPE offers a variety of flavors and formulations, including original mint, cinnamon, and bubble gum.