If the information you have is genuinely confidential, then you could discuss what to do with the manufactuer.
Some manufacturers are willing to work with people that handle strictly confidential data and form an individual arrangement. E.g. manufacturer agrees for customer to destroy drive to their satisfaction, and RMA the remains as proof that the drive as been destroyed.
Some manufacturers are willing to work with people that handle strictly confidential data and form an individual arrangement. E.g. manufacturer agrees for customer to destroy drive to their satisfaction, and RMA the remains as proof that the drive as been destroyed.