So this is the very best cleaning tool I have found. Ever since we moved into our new house, I have been trying to get the upstairs toilet clean - with not much luck. I tried pretty much every kind of cleaner I could think of, but nothing really even made a difference. Finally, I'd just decided we'd have to save up and get a new one. But, I found some site that talked about these pumice stone sticks and figured I'd give it a shot - and now, after a bit of scrubbing, we have a sparkling white toilet again! :)
Also, when we moved in, we took off the shower doors in our downstairs bathroom, which left a ton of gross million-year-old calking that would not come off for anything. Tonight while I was in the shower, I tried this out, and off came all the gross stuff at last!! Hooray for a great solution to a yucky problem! :)