How secure erase the SSD

You have already decided on the answer you want, and seem uninterested in technical details. So go do it.

If you want to understand a little more…

If the in-built data encryption is insufficient, shred the Mac. macOS uses your password to access a robust generated encryption password, and the storage-erasure procedure steps on the keybag. That makes the data inaccessible. Quickly.

Otherwise, format the volume and re-install macOS, as suggested by Apple. Or erase the volume using a new feature of Monterey, as suggested by Apple.

If the standard and fundamental behavior of an SSD—the integral erase-on-write behavior required for all flash storage—is insufficient, and/or if your data was somehow unencrypted, then you will want to physically shred the storage. Writes do not overwrite the same storage, the writes re-vector the write elsewhere. This for wear leveling, and for performance.

There is no storage-overwrite capability with SSDs, and the multiple-pass-overwrite I/O scheme dates back to external-servo hard disks and floppies from the 1980s; when head-tracking was sloppy, at best.

Here’s the Monterey feature, with links to other info:

Erase all content and settings on Mac - Apple Support

Info on keybags and how Apple storage encryption works:

Apple Platform Security - Apple Support

Short answer: Yes, your suggested approach will work.

It will, however, require whatever time it takes to write what I assume to be several hundreds of GB of data necessary to fill your SSD.

There will be no need to do it more than once because, again... solid state drive.

imho, you're going to an awful of of trouble for no good reason.

The nature of data storage on an SSD is pretty darn secure. If you simply erase or repartition the drive then the data is pretty much rendered unreadable.

Still, there's this light reading:

How to Securely Erase Your SSD Without Destroying It - makeuseof.com

"I remember I read somewhere that specialists can recover data when it's overwritten a few times, but it apparently gets very difficult after about 8 passes (all from top of my head). "

This is specific to magnetic media only, i.e. magnetic tape, floppy disks and hard disk drives. It doesn't pertain to SSD drives.

SSDs do not require secure erasure due to the nature of the way those storage device retain data.

That's why you won't find a process for it in the macOS.

The reason it is used on magnetic media (HDDs) is because data on those drive leaves behind magnetic trace unless that trace is destroyed by overwriting it several times (securely).

IMHO - doing a Secure Erase of an SSD is basically a waste to time and increased the chances of Destroying the Drive.

Even if some data was left behind after a normal Erase and someone was able to get the drive to Professional Data Recovery Company - they will tell the person the chances of recovering any meaning Data is extremely low if not possible at all.

There is nothing we can do to convince you not to electronically shred your drive, so by all means go and shred it.

If your data is encrypted as you say, then just destroying the encryption keys are enough to prevent access to the data since there is no way to decrypt the data without the encryption key. This is the whole point of encryption.

With an Apple SSD once you use Disk Utility on macOS to "erase" the SSD (simple erase) the TRIM support on the SSD will automatically clear out the NAND cells. I'm not sure what happens when using a third party SSD. You can check the contents of the SSD by running the following utility from the Terminal app although you will need to replace "diskX" with the proper drive identifier for the SSD):

xxd  /dev/diskX

I'm not sure if "xxd" is available while booted from a macOS installer since the installer is quite limited. You will see some data on the SSD for the partition layout and a few hidden macOS support files, but the majority of the data will show as zeroes and dots.

If you have a 2018+ USB-C Mac, then the SSD is hardware encrypted. If you "Restore" the T2 firmware, then I believe it creates a new set of encryption keys which effectively instantly destroys all data on the SSD since without the old encryption keys there is no way to recover any data from the SSD.

Revive or restore an Intel-based Mac using Apple Configurator 2 - Apple Support

Revive or restore a Mac with Apple silicon using Apple Configurator 2 - Apple Support

About encrypted storage on your new Mac - Apple Support

Depending on the exact model of the Mac and the SSD used, it may be possible the SSD has a built-in hardware secure erase feature, but this can only accessed from a bootable Linux USB drive and may require several command line commands to execute. Not all SSD's have this feature built into them. I have successfully performed this procedure on Apple 2.5" SSDs, and on many Apple blade SSDs from 2013 - 2015, and was only able to do this on a few of the 2016-2017 USB-C Macs.

No matter what option you choose, you still must trust that the SSD is doing as it has been told. Even using "xxd" to read the raw data from the drive can be misleading as some SSD's are programmed to show zeroes after a secure erase even if the data is not erased. I would expect the major SSD manufacturers to be the most trustworthy & reliable in this manner especially if their SSDs have been tested to comply with the hardware secure erase feature.

If your data was encrypted, then you have nothing to worry about once the encryption key has been destroyed.