I was involved in multiple attempts at "net-boot linux and let the local user be root", what works best is exactly what is mentioned in the article: just wipe the thing each time.

But there are different approaches to this: on one extreme you can boot minimalistic linux from PXE which does moral equivalent of "curl ... >/dev/sda" on the other end you can run from ramdisk. The ramdisk approach works very well, but is neccesarily limited by size of RAM.

For our anime conventions we have our own "linux distro", that consists of debian unstable with quite involved rewritten initramfs which obtains the root image from somewhere (file on USB storage, which can be optionally mounted directly, or downloads the image using HTTP) and pivot_root's into that. Being able to boot Linux on ThinkPad without any persistent storage to speak of and being able to use it completely offline (the whole infrastructure for this to happen is only on our internal LAN, not on any kind of WLAN) is somewhat magical.