Degausser - or demagnetization.
Unfortunately, a hard disk degausser doesn’t work.
It sounds so nice: you take a giant electromagnet, put your hard disk in it, and you’re done.
Then we call it a degausser.
However, the hard disk manufacturer has made sure that the magnetic disks are in what is called a Faraday cage.
That is, the place where the disks with information sit that is totally shielded from all kinds of radiation.
Now the manufacturer of the degausser promises that precisely HIS degausser is strong enough and reliable.
But you never know for sure