Solved Destroy ALL HHD data

[Chalky Emultion]

Hi, I'm going to sell some old hard drives.
To keep my data off them i first used Ccleaner to clear all data with overwrite feature, then I did a low level format on the HHDs.
Then I was unable to find any trace of data with DiskDigger.

Is it enough?

 

[Golden]

Perfect.

 

[Chalky Emultion]

Perfect.

Thank you