Did you know WD-40 is a great toilet cleaner for hard water stains?-WD-40
Noble Chemical 1 qt. / 32 oz. Valient Ready-to-Use Disinfectant Toilet Bowl Cleaner - 12/Case
ZEP 32 oz. Acidic Toilet Bowl Cleaner ZUATBC32 - The Home Depot
How to Clean Mineral Stains From Your Toilet | HowStuffWorks
How to Remove Hard Water Stains in Your Toilet Bowl
The Works Antibacterial Toilet Bowl Cleaner, 32 fl oz - Kills 99.9% of Bacteria, Removes Rust & Lime Scale, Deodorizing Formula in the Toilet Bowl Cleaners department at Lowes.com
Amazon.com: Lime-A-Way Toilet Bowl Cleaner, Liquid 16 oz (Pack of 2) : Health & Household
Clorox® Toilet Bowl Cleaner with Bleach | CloroxPro
Iron OUT® Automatic Toilet Bowl Cleaner — Atlas Preservation
Lysol Power & Free with Hydrogen Peroxide - Toilet Bowl Clea