[Q] Q: How to be sure to completely remove all the data before selling a device. topic

Hi everyone,im having some money issue..not going into the details,and i need to sell one of my beloved android devices.
The fact is that im paranoid (because i know that you can recover all the data after a wipe) So im looking for a way to delete 100% the data on the phone IN A WAY THAT IS NOT RECOVERABLE. I have tons of sensible information,even of my workplace that i really can't risk to share.

The phone is rooted with a recovery installed.

Thanks for the time,hope someone can help