so, it's not for newbies? It's this?

eroize device (destroys user data)

The following commands will securely erase your phone such that no data can be recovered later, then restore the operating system and provided content.

Warning: The secure erase feature has not been audited by a 3rd party. Do not rely on it to protect all traces of highly sensitive information from a well-funded attacker. The first part will take a very long time - let it run overnight.

Code:

flasher -f -F main.bin --erase-user-data=secure
flasher -f -F main.bin -F emmc.bin --flash-only=mmc

The code must be written in that way? In main bin and emmc bin have to change something? Once made the zeroize I have to reflash the firmware? which firmware must reflash?