[Dovecot] Administrative mailbox deletions

I'm in the process of nuking a bunch of dead mailboxes after they've been migrated to other servers - but the accounts have been kept.

A simple shell script takes care of most of it, BUT.... (there's always a "but" isn't there?)

One user has named all his mailboxes with leading hyphens.

ie:

-foo -bar -bazz

and "doveadm mailbox delete" doesn't like it.

Does anyone have the magic sauce needed to escape the - character?

Thanks in advance Alan