Why not just leave the small file on there? It's a lot easier to do that then try to get a factory fresh format on it. Otherwise, I would recommend going to Iomega, telling them your needs, and as long as you're willing to buy them in bulk, you should probably be able to purchase a number of disks without the file. Also, if you want to do a secure transfer, why not just use CD-Rs? They hold more, are much less expensive, and don't have any files on them to start with.

AJ