Amazon.com: STAR BRITE Toilet Bowl Cleaner - Formulated for Boat & RV Use - Removes Stains from Plastic & Porcelain Bowls - Doesn't Interfere With Most Holding Tank Treatments (086416) : Automotive
Unique Flush-It 2-In-1 RV Toilet Bowl Cleaner and RV Black Tank Treatment (15 Foaming Enzyme Pods) - Walmart.com
Pure Power V23500 Toilet Bowl Cleaner - 24 Oz
RV Toilet Bowl Cleaner and Holding Tank Enhancer Liquid 24 Ounce - Removes Stains and Odors in All RV Toilet Bowls - 41F-1 RV Plumbing - Newegg.com