I've never done this personally, but I believe Apple's Disk Utility has a function to zero out drives. In theory, if you boot into Recovery Mode (Which, IIRC, w

I've never done this personally, but I believe Apple's Disk Utility has a function to zero out drives. In theory, if you boot into Recovery Mode (Which, IIRC, was Command+R or holding the power button on ARM machines), you can access the utility and shred the drive with Disk Utility and then reinstall from there.