If I put a magnet to one of those old floppy disks or to a hard disk drive would that in effect be a secure erase?
But interesting when I put a magnet on a hard disk drive platter the magnet had no “pull” effect on it?? Perhaps the shiny silver color coating deflects the effect of magnetism??
Friends say to use a hammer to break a hard disk platter is the easiest and most secure, but sounds messy and a bit dangerous/hazardous to me with pieces of hard disk flying everywhere.
— Luba
Magnets won't do much. They might erase a few bits and mess up the drive, but not really erase it. There are professional electronic magnets that do a much better job...
But the easiest is to hook it up to your Mac and run Disk Utility. there you can erase and overwrite the dive with zeroes. There are some programs you can use to overwrite with random numbers, but that is overkill unless you have state secrets and have people spying on you.
I have done the hammer-to-the-drive thing before, when I had a drive so old it could no longer be used with any current machine. It was fun, but I wouldn't do it if you are worried about it.