Wiping external HDD's with Apple Disk Utility not working

[bear_in_mind]

I've been trying to wipe several HFS+ formatted external HDD's with Apple Disk Utility, but it's not working.

The drives were in working order before attempting erasure (in preparation to donate the drives to a non-profit). They still mount, but they began the erase procedure for about an hour, then stopped.

Now, I can't erase or initialize them using OS 10.6 (Snow Leopard on older MBP) or 11.7.1 (Big Sur on Intel iMac 5K w/ factory SSD). I receive the two following error messages when trying to securely erase data with either system:

1) Couldn't open disk (-69759)
2) Couldn't open disk (-69879)

Should look at buying third-party software (?) or if there's another option you can suggest besides ripping the drives out of the housing and hammering and/or drilling them, then take them to an electronics disposal site?

 

[Fishrrman]

Something you could try (no promises).

Connect one of the drives that's giving you a problem.

Open disk utility.

Click erase, BUT...

DO NOT attempt to erase to HFS+ (yet).

Instead, choose a "PC format", like exFAT with Master Boot Record (if that's available).

Does the erase "go through" this way?

If it does, NOW go back and re-try to erase to HFS+.

Any better?

 

[bear_in_mind]

Thank you so much for the suggestion! Will give it a whirl this weekend and report back.