I typically won't sand a full hollow. Instead I cut off the active rust with a single edge razor blade, then some 0000 steel wool and oil/ WD-40, then 3M metal restorer/ polish.
After cleaning up 50 or more razors, you'll be better at evaluating if a blade warrants sanding at all. Most aren't.!
1/4 hollow and wedges are the only blades that can withstand heavy sanding. I also don't go any lower in grit, than 400, only on great occasions do I drop to 320.
Making a magnetic blade holding jig is a must, for hand sanding. Let's you use both hands while sanding, and lessens the fatigue .
