The systemd-cryptenroll man page states:
Takes a comma separated list of numeric slot indexes, or the special
strings ..., or any combination of these strings or numeric
indexes, in which case all slots matching either are wiped.
but we'd allow only one special string at any given time as the value
was not ORed when assigning. So, for example, --wipe=recovery,password
would actually become --wipe=password, etc.