Review on 10 Ounce Diamond Shine Professional Window and Glass Hard Water Spot Polish - Ideal for Car Windows and Shower Doors - Effective Water Cleaner by Sherry Elliott

This is a fine diamond powder abrasive that can scratch anything if used incorrectly. Basically you buff stains and heavy dirt. You need to use enough varnish so that it doesn't dry out when you apply it in a circular motion. Although I think it's important to just overlap the movement as most of the time you'll be buffing the glass up and down and then side to side for guidance, so don't just go back and forth. Even distribution of direction during application helps with buffing instead of working with directional grooves. So apply a little for fine cleaning and keep reapplying to keep it moist. It seems to work just like the other products I've tried, but it's definitely prone to user error and misunderstandings about what it is and how it's supposed to work. So if you don't know, watch YouTube videos on how to use glass polish to clean your glass surface, but don't be alarmed if they use a polishing foam sponge and a power tool, you don't have to use that. A clean microfiber cloth and some elbow grease will suffice.