My sink was stained up and had irremovable hard water/corrosion
stains. I went to home depot and found a $10 sink polishing kit. It
has various grades of sandpaper. Amazingly it took everything off and
restored it to like-new condition. Hardly took any elbow grease, just
15 minutes.

Anyone know what grit sandpaper they use ? I want to buy some more to
clean up some of my bathroom fixtures. Or should I just buy another
$10 kit?