wiping a hard disk in Linux

using dd

https://how-to.fandom.com/wiki/How_to_wipe_a_hard_drive_clean_in_Linux#Wiping_specific_files

several hours?

https://superuser.com/questions/262056/how-long-to-zero-a-drive-with-dd

https://unix.stackexchange.com/questions/9432/is-there-a-way-to-determine-the-optimal-value-for-the-bs-parameter-to-dd