My bathtub has never been whiter!! Works great on glass shower doors too- no more soap residue! Martha Stewart's Tub Scrub--works better than any other cleaning product to get off hard water and soap residue. 1 cup baking soda, 1 teaspoon dish soap, enough water to make a paste.
Tub Cleaner - Heat 1/2 cup white vinegar in microwave for 90 sec, pour into a spray bottle. Add 1/2 cup BLUE DAWN dish soap. Shake gently to mix. Spray on surface, let it sit 1-2 hours. Just wipe it away then rinse with water. Should also take soap scum off shower doors and tile! THIS STUFF IS AMAZING!