[sborra]

What about the chemical option - attacking the board with a strong acid. Are there any readily available acids that would do the trick?

[semi-extrinsic]

There are several more-or-even-more nasty chemicals that will damage PCBs to various extents. But none of those methods should be undertaken without using either a supplied air full-face mask or a proper fume hood, and all of them leave you with the problem of safely disposing of nasty chemicals at the end. Mechanical destruction is cheaper and safer.

[rwmj]

I immerse my old HDDs and SSDs in full sugar Coke.

[andai]

I know you're probably joking, but would this actually work? I know it dissolves teeth.

[rwmj]

I'm not joking! Full sugar soda is cheap and readily available, it's acidic and it does appear to damage the electronics. In theory at least the sugar should also gum up the innards of HDDs.