I finally figured it out! It's all about the technique. The 3 things you need are:
Here goes:
First, pour just enough water from the bucket into bowl to get it to flush (I use an empty 33.9 oz. plastic Folgers container, poured as quickly as possible). The water level in the bowl will now stay in the bottom of the bowl, and this eliminates the need to turn off water supply (which can be a hassle). Spray all around ring with cleaner.
Now go clean the tub, sweep floor, empty trash, get coffee, or whatever. Come back to the toilet ring in 30 minutes or so, and scrub ring with brush. Part of ring will probably be gone...maybe all. A stubborn ring will be lighter. Flush. Repeat as many times as needed. I had a stubborn ring that I'd tried everything on. It took 4 times to get ring completely gone.
Now I keep cleaner, brush, bucket nearby. Once in awhile before bed I'll pour bucket, spray ring, and go to bed. Rings don't stand a chance!
By Rob S. from Fairborn, OH
Used properly a pumice stone is the perfect tool to remove toilet rings. This is a page about using a pumice stone on porcelain toilet bowl.
This is a page about "Where can I buy a pumice stone?". Pumice stones can be used for a number of cleaning jobs.