Yes you can brake them down and make more money...or sell them from 60 to 70+ cents a pound with out having to do anything to them. That's the same as clean AL if not better than what some people get. So its really on what you want to do...we use to brake them down our selfs...but we don't anymore...it takes alot of time..and that time can be used to do something else that would make more money in the long run.
If you take them apart then this is not an issue and a good point to bring up...this is something that should and should be done. But the hard drive in the chiller and chill it around 18F it will lose all data...drive could still be used.
We have done this to very large drives (over 500gb) before we resell. Even drives that are locked up this can "fix" it. What happens when you chill them down like that they will lose the magnetic field on the disks. Because the disk have a very low magnetic field it is easy to kill with cold.