Always use water to lubricate and, of course, use the black wet/dry sandpaper. Dry sandpaper cuts too quickly, too roughly and is VERY BAD for your lungs, if you want to be doing this for 10, 15, 20 more years. OR just if you want to be breathing for 10, 15, or 20 more years.
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"Just because you can do something does not mean you should do it."