get a $2 stripping brush from the paint department of any store for cleaning rasps and files. stiff nylon easier on your rasps and files than file card.
when I put my tools up for any length of time, like during hunting season, I brush them clean, blow them off with compressed air and hose them down with spray silicone. does a nice job of keeping corrosion at bay. sawdust and such left on tools draws moisture, which encourages rust. saw and jointer tables get blown off and wiped down with silicone, too.