Scrubbing Bubbles Vanish continuous clean, drop-ins. Repels tough hard water and limescale stains. Simply drop a tablet of the toilet bowl cleaner into the back of your toilet tank. With every flush, it cleans and deodorizes your toilet bowl and repels tough hard water, mineral, and lime scale stains. Helps keep your toilet bowl stain free for up to 12 weeks. 3-pack. Blue.