>>Would not bet large sums against motivated adversary...
>>Strip the casing to see chips, identify memory (size should do it),with that: increase surface (pulverize best, drilling holes plus hammering ok, melt/burn remains
>
>I know that a 20lb hammer would do just as good job as a microwave :). But I need it to look like new :)

Buy a new one of the same brand and model, format it and submit it to wherever it needs to be blank and new. Then return to the old one. Don't use force, use a larger hammer.