I have tried EVERYTHING, Bar Keepers Friend, spot remover from Mitre 10 as well as a number of supermarket products and nothing worked. This is the miracle product I wish I had found years ago! Using the drill pad included with Shower Hero together did the job it is 100% clear, I had 20 years worth of water stains that scrubbing just couldn’t remove, in this photo I have cleaned a hand size spot, I only wish I could share my video