I put the unit in my basement bathroom, A bathroom that is not used on a daily basis. There was a film coating the bottom of the toilet from the water just sitting idle...no longer a film. So I would say it is working great.
I received my order of two unit. I put them in my tanks immediately. As promised, the stains in my toilet stayed away. I made sure they were cleaned to start with. This product will not remove stains already in place but will prevent them from coming back.
At first I didn’t follow directions, but as soon as I bought and used scrubbing bubbles foaming bleach my toilet stains disappeared
Product is working as advertised. Still a few weeks to go to know for sure.