[Dovecot] purge maildir folder after sa-learn

Hello,

I am looking for a command-line utility to automatically purge one Maildir folder. I want to periodically run sa-learn from cron, and after the spam learning folder has been added to the Bayes database, its contents should be deleted. I've searched a bit, but only found a few old utilities or some telnet+expect scripts, which both didn't look too reliable.

Is there any command-line utility to delete all contents of a Maildir folder, or is there any other solution?

Thanks, Florian