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