Chestnut
I was going to suggest leaving it in water for a day or two. Would that do the trick 'railman or would it spring back to life when it dried off?
I have a hard drive and some memory sticks I need to smash. I keep trying to muster the courage to go outside with a hammer, but if water will do it that would be much easier.
I've also considered buying a fire pit and burning them. Might also be useful for old diaries and letters, of which I have a lot.
Chestnut Just to be sure - if you have a garden waste burner, or 'fire pit' that would also do the job well.
Some data can be recovered from dried out drives, so 'drowning' them will work to a degree, but ....