@ricleo2
I am curious: How did you go about writing data to 4 "bad" drives?
How did you determine that the drive is bad and not erasable?
What make, model, and capacity drives?
Did you try running the applicable manufacturer's diagnostic software on the drives?
What software did you use to write the data to the drives? What error messages did you get?
Overall, if the data is actually there and you are concerned about it then keep the drives.
Just let younger family members take the drives apart for the magnets and platters. All will be lost soon after.....
Recycle the drive bodies and remaining components.