The HOUND DOG is a great product that has been around for years and it really does work. Unlike a lot of supermarket brands, this product does what it says and you do not have to continually go back to the problem. I use it on shower screens at work and they stay clear for a long time especially if the screens are wiped down with a squeegee after use.
I highly recommend this product to anyone who may be after a reliable hard water stain remover.