Often tried, but seldom works as well as promised... and certainly not to a miltary grade of security (if there is one yet).. but not to Federal standards, for sure.
Have worked on many projects where this was attempted. They were all laughers.
Think about it. If this really worked, everybody would be doing it.
To remove them from circulation, use an electric drill and a good bit.
To make them re-usable, just reformat them a three times. Nobody knows how to recover from drives from which they do not know the source.
It has been proven many times that degaussers (magnetic systems) don't not work nearly often enough. Hard drives have such strong shielding that the magnetic oersteds (Oe) used to destroy the data can only achieve a high enough field intensity to destroy the read-write arm. Therefore, it's often possible to remove the platters, so the bad guys put them in new disk housing with a new read-write arm, and read the data that you thought you had destroyed.
The new disk shielding technologies have made degaussers unreliable at best.
Reformatting a disk can wipe out the data, but reformatting a disk is very time consuming. It can take hours to reformat one disk. And the system reformatting the disk needs to be operational. The Hard Disk Crusher can destroy a disk and the data on it in just seconds without the need of a peripheral PC or workstation.
True, that a very good technician can recover a formatted drive when he has special equipment... but when nobody knows the source of the drive, that effort is relatively futile.