Polishing is a gradual scratching process using finer grades of abrading material to gradually remove the previous scratches. As a metallurgist in the steel industry we polished samples to view down microscopes using fine diamond abrading spray on soft pads to get rid of final marks.
When polishing, the technique was to get uniform scratch lines then rotate the sample 90 deg and repeat with finer abrading material until uniform scratch lines, but finer, were obtained.
Repeat as necessary using finer abrading media. We use normal wet and dry papers to start. Depending on the metal we ended with varying final media, diamond for steel or hard metals and jewellers rouge for softer.
Autosol, Brasso, car detailing polishes are varying grades of abrasives in liquid/paste form.
Coffee or tea stains in a mug? Make a paste of bicarbonate of soda ( sugar, salt would do ) but just enough water without any dissolving. Rub that round the stained areas. Very mild abrasion to rub off stains. I just bottled some beer, I used clean sharp sand with water to shake inside to flush the glass before final washing/sterilising.
