I attached a couple of rare-earth magnets to the front and back of my Gen 2 clamp and collected almost no metal particles over about a six month period. Gave up on them as useless.
On my Gen 3 vise, I closed up the open sides with tape to exclude any infiltration of metal or abrasive particles.
Between grits or for viewing with my USB microscope, I use a Swiffer duster – two quick wipes, one on each side. I’ve had outstanding results with it. Try it. You’ll like it!
The Swiffer is an outstanding dust attractant, as opposed to other rags, which might drop their collected particles where you really don’t want them. The Swiffer gobbles ’em up and keeps ’em.