[Spambayes] How to retrain from scratch in pop3 web interface?

[skip at pobox.com]

I've used the pop3 proxy's web interface as the GUI for a SpamBayes plugin
for Roundup.  While I'm the author of the code, other people are responsible
for actually twiddling the bits on the server, so I have no access to the
SpamByaes instance except through the web interface.  I don't see any way to
retrain from scratch via that interface.  Am I missing something?

Thx,

Skip