to military spec.
I’m not sure all militaries would agree. I once worked, briefly, on a highly secure project. The development process was closely audited by the customer so when it came time to replace a disk, we had to courier the old drive off for them to ‘sanitise’ to their satisfaction. A few weeks later they returned our disk, with the individual platters packaged separately from the disk, having bad the magnetic coating ground off completely.
I daresay they overwrote the data and degaussed it thoroughly before grinding, but at that time at least (a few decades ago) grinding of platters seemed to be also a necessary final step.
Not sure about dban as I can’t open that link (temporary problem, i suspect) but one problem with attempting to trash a disk just by overwriting it is, any data that is in defective and remapped sectors may not be overwritten, but could still contain data that could be recovered. With SSDs there is the additional problem of wear levelling algorithms. Again though, unless you are a seriously wanted criminal, or head of state engaged in international conflict, or a journalist related to such topics, you probably needn’t worry too much.
CarlIT’s ‘trim’ link seems the way to go for SSDs, but not sure if that would work if the drive was already ‘dead’ and unresponsive to the UI, with the possibility of data remaining in the individual chips within?