Yeah the cheapest way, too bad the rpi 4/5 and future versions make it possible to write to the eeprom. Atleast it sounds like the newer ones have a way to make it write protected via a jumper or something.

You can look here might find a place near you that takes plastic https://community.preciousplastic.com/map I've been looking at getting something like this to recycle my own filament. https://felfil.com/?v=5ea34fa833a1

There is a great talk from the Lavabit CEO who discusses what happened to him and his company when they found out Snowden had an email at his company. I won't link it since it's YouTube but it's an hour long but he talks about his experience with the FBI and the courts. You can search for M3AAWG 2014 Keynote, I highly recommend it.