I only added this on to get the free shipping and it was totally worth it. We have an acrylic textured bathtub with glass doors and it not only cut through the white deposits on the glass, but also the dirt embedded in the pebbled texture with minimal effort. Much easier than the soft scrub I had been using with unsatisfactory results. There was a bit of a haze on the glass where I didn't rinse it off completely, but even then it looks better than the white mineral deposits and is easily rectified with more rinsing.