When I have to go through piles of floppies (and I do this more often than I care to) I make a master iamge of a good floppy and then copy with format+verify, aborting on the first error.
The reason is quite simple--floppies with bad spots never get better, they only get worse. So you might as well bin the ones that don't pass the test. I have a special machine set up with 3 floppy controllers that can write 3 disks simultaneously--disk changes are triggered by simply removing and inserting floppies from the drives. There are 6 drives on this machine, so the work progresses pretty well. My take, anyway. --Chuck