[gedster314]

I'm posting from the phone so I can't give links. Goggle "dd linux". It's an old command that goes back to the 70s. It was used to write data to and from tape, programers just kept adding functionality when needed. It makes a true bit for bit copy of a disk. If you tell it to copy from a null or zero drive it will fill a drive with zeros.
Then just format as usual. I've saved a few flash drives that were destined for the trash with it.