Cratex comes in about 3 different grits- - - -I believe the brown ones are coarse, gray is medium, and white ones do the mirror polish I like on trigger sears with the letoff weight measured in ounces on target rifle triggers. For a little more aggressive rough-out try the Roloc abrasive discs in 1 1/2" diameter that twist onto the flat rubber backing discs. They're available in the 1/4" shank diameter that fits the die grinder collet.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!