I've tried echoing to detach and stop. The device will remove itself, but will show up again on reboot. One time on reboot, it restored the mdadm raid I had as a backing device!
The other time I disabled the ramdrive that it was paired with, did a detach. And /dev/bcache0 came back up again after reboot.
There is no unregister under
I've also looked in /sys/fs/bcache... /sys/block/md0/md0p1/bcache
for this non existent unregister.
only register and register-quiet
I even uninstalled bcache-tools, and /dev/bcache0 still shows up after reboot and is caching /dev/md0!