Bests & Worsts Reviews from Amazon

This stuff is great. I tried everything I knew to reduce hard water stain buildup on my glass shower doors. I came across a youtube video about allowing vinegar to soak on your faucets or surfaces for hard water stains with calcium deposits to be removed. I could not just spray vinegar on my shower doors because it would basically just run off and down anyway. So because this stuff is basically oxalic acid, I figured it could be mixed with another cleaning acid (vinegar) safely to make a double strength cleaning paste. It worked. I used about an ounce of this cleanser with a 1/2 teaspoon of vinegar and mixed well into a thin paste like consistency or to the point where I knew it would adhere to the glass without running. I applied the paste with a paper towel and left it on for about 2 hours or maybe more. I used a damp magic eraser sponge to see if this would be enough and what'll you know, all the hard water, calcium deposits that barely budged from previous many cleaning attempts was wiped clear off and the glass looked brand new. No elbow grease needed. Just normal wiping. I hope this helps someone else.