[allenz]

Entertaining talk, but the best method is to discard the key for your fully encrypted disk. It's 2017, all your disks use FDE, right?

[zaarn]

SSDs internally yes. Any modern SSD simply uses some random key unless you specify another one. Shredding is as simple as telling it to shredder the key, end of story.

Some harddrives do this too, I believe but it's not as widespread yet.