Ok, this is embarrassing but I have to share. Our upstairs hall bathroom rarely gets used except for showers. The toilet runs almost constantly (need to call a plumber) and we have hard water. I've battled hard water stains forever. I clean frequently and keep a self cleaning bar in the bowl.
Believe it or not this is a freshly cleaned toilet....yikes!
I had heard of pumice stones working well so I ordered the product below from Amazon. It got great reviews.