how to clear all local caches for a group?

[David Abrahams]

In my agentized nnimap groups especially, if messages are deleted in
other mail clients, it's very common that gnus still thinks they're
hanging around (and often the number of messages it reports is
different from the number of messages it will actually display) no
matter how many times I invoke gnus-agent-regenerate-group and
gnus-agent-expire-group.  Is there some brute-force action I can take
to make Gnus treat the group as though it's never been opened?

Thanks,

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com

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