[bshipp]

Shredding/sledgehammer is likely the best option for secure disposal of mechanical drives, but SSDs are a different animal and are likely reusable given some of the suggestions in this thread.

[fdeee]

Not really. HDD recoverability is a myth, anything overwritten isn't coming back with modern HDDs. Bits can't "bleed out" anymore, density is far too high for that.

The thing you need to guard against is relocated/reserve sectors, in HDDs same as in SSDs. The proper way to do this is full disk encryption, and if that's not possible, physical destruction.

[hedora]

Most hard disks support hardware level encryption and full disk erase at this point.

There’s very little need to sledgehammer anything given realistic attacker models.

[fdeee]

Both, HDD/SSD encryption in hardware and secure erase have been proven untrustworthy numerous times.