People need to be aware of the computer forensics method called
`Magnetic Hysteresis' whereby magnetism can be traced back 10's of
times so that even a formatted disk can be re-read.
Modern programs can re-write the disk 30x times to permanently avoid
this, and modern drives try to avoid it because of the risk of
cross-talk on higher density platters.
However, the only safe option which avoids some smarta$$ finding a new
forensic method is to lathe the drive into dust.
As for your method, X-ray, I would use at least a .50 hollowpoint...
:-D :-D :-D
Desert Eagle maybe...
;-)