Neverware disables "Powerwash" everywhere in the UI of CloudReady in order to avoid any strange behavior for users - especially those who have Chromebooks that are enrolled in management.
However, it turns out that (for users of our Home Edition) it is possible to completely wipe the stateful partition (equivalent to a powerwash) from the cmd line. A user on https://reddit.com/r/cloudready posted this trick recently:
... after digging around in the init scripts, I discovered that writing: "clobber" to /mnt/stateful_partition/.update_available will initiate a powerwash on reboot ; so CTRL-ALT-T into crosh and enter a shell ;
shell sudo echo 'clobber' > /mnt/stateful_partition/.update_available sudo reboot
... your Cloudready install will wipe itself and you can start over.
In my experience, for some reason, it was necessary to use
in between the first and second cmds above.
Of course, we always recommend a fresh install from USB for the most complete reset.
Hope this is helpful!