Logically, I would assume no. If people swap in different USB sticks, it is even impossible to wipe them all because some of them not even plugged in :-)

Personally being able to get the drive into a known good state seems like a good idea.  Perhaps to overcome Michael issue the drive could also be reinitialized when inserted for the first time.

If no agreement can be reached perhaps we can have a script/ui option to "reset/initialize" the external drive

Regarding getting the external drive into a well-known
state:  Yes, that seems a good idea.  Regarding using powerwash:
Not so much good.

I have two concerns with powerwash:
  * It feels unnecessary.  We use powerwash for stateful
    because we can't easily re-create that file system except
    while the system is down.  That's not true of external
    moblab storage.  For that, we can just stop a few services,
    unmount the file system, and re-run mkfs without stopping
    the whole world.
  * It feels dangerous.  Powerwash is a consumer-facing feature,
    and for consumers, wiping external storage during powerwash
    is something that simply MUSTN'T be done.  So, we'd want to
    structure the code so that "wipe external storage" doesn't exist
    outside of moblab.  That feels like work, but any other option
    feels like an opportunity for really bad user experiences.  So,
    avoiding this altogether feels better.

I think the real answer is to detect are we in a fresh state (this can be done by seeing if the database is being initialized and setup for the first time) AND are we using an external drive.

If so, wipe everything on the drive prior to using it.

Now we covered the powerwash case as that caused the database to be reinitialized.

NextGen moblab will not need an external disk so this use case is unlikely to be worked on - closing for now.