I’m assuming it’s the hard stick/cake type of stuff. Use a small felt disk, start your tool at low speed, grind into the stick to load abrasive on the felt. About 1 second’s worth is all you want. No water involved. Should be fine on your razor, buff a little on the spine to make sure and to get a feel for what it will/will not do. Recharge the abrasive whenever you feel the need as you are buffing. If you are getting black residue on the blade you are using too much abrasive. Dremels and other rotary grinding tools have a love/hate following here, mostly hate. Yes, you can really clean up a blade fast and get that mirror finish if you are super anally careful. Very nice. BUT – you can destroy a blade far easier. It is very easy to overheat a blade and lose the temper/hardness of the steel. This is especially true on the thin cutting edge of the blade. We are talking seconds here. Buff for only a moment at a time, moving to a new spot constantly. Go back many times verses doing the same place till it shines. The bigger danger is catching an edge and snapping off a chunk of your razor. Common sense tells you the rotation of the felt pad needs to be from the middle of the razor to sweep off the side or end of the blade. Most of the time this works, but occasionally you will still not roll off the razor quickly and cleanly. Something will catch and your spinning edge will pull the blade onto itself at an extreme angle. This generally occurs coming off the sharp business edge. You thought you were being soooo careful, then you hear ZING, feel the blade ripped from your fingers, and see a half inch of steel missing. Blade destroyed, hopefully same cannot be said of one’s eyes or fingers. And this is all if you got your stuff together. Seems like most people decide that hand sanding is much less dangerous , both physically and fiscally. So, good luck, just be very careful.