I recently had a new toilet installed, and the manufacturer placed a sticker inside the tank warning against the use of in-tank cleaners. The sticker says that “these products may cause serious tank fitting damage which may result in water leakage and property damage. Proof of using in-tank cleaners will void warranty”.
Are these cleaners really that dangerous? I have seen them used over the years without being aware of any such damage.
For many years I have used something that gives the color a blue tint and have never had a problem. OTOH, I guess some oproducts could be corrosive and that is the reason for the warning.
The ones with chlorine in them deteriorate the flapper and the seal between the tank and bowl (This is what “…tank fitting damage which may result in water leakage and property damage” is referring to.) They also hamper the growth of the right kind of bacteria in a septic system.
Don’t use them.