Drano Clog Remover is designed to unclog a drain quickly and efficiently. It contains chemical designed to dissolve hair, soap, and gunk. Drano Clog Remover should be used to unclog kitchen sinks, bathroom sinks, showers, and tubs. It is not designed for use on toilets. Drano Max Build-Up Remover is designed to prevent build-ups and clogs from happening. When used regularly it will keep drains from creating build-up. Drano Max Build-Up Remover is for use in drains, toilets, and septic systems.