I’m fine on the concepts, but I know I will need some of the specifics of this eventually. From gizmodo.com of all places, comes a bunch of free ways to thoroughly erase hard drives, ssds and thumb drives, moving from very secure to totally secure to insanely secure. Article focuses mainly on zero-fill software from different hard disk makers and secure wiping various devices.
I should confess that some of the alternatives promoted in the comments gave me quite comprehensive belly laughs. No, shooting a drive on a rocket on a trajectory towards the center of the sun was not one of the suggestions offered to efficiently wipe it, but a few of the tips come rather close!
