Noob Question: SeaTools Sanitize Overwrite before selling old HDD's?

Hi all!

Just upgraded my Asustor 6TB drives to 12TB and wondering if I have scrubbed them correctly before I sell them on? Given they are Ironwolf NAS drives I used SeaTools and the "Sanitize Overwrite" function. Took probably 12+ hours per drive to perform.

https://www.seagate.com/au/en/support/secure-erase-matrix/

Appreciate the advice everyone.
Cheers!