Need way to clear/reset allocated xvnc ports - groovy?

See here:

http://stackoverflow.com/questions/31481107/jenkins-xvnc-plugin-some-display-numbers-stay-allocated-when-a-build-is-stopped

I'm having the same issue. I can probably get this done during a scheduled outage on the jenkins master, but that's really invasive. Is there any way to call a function via groovy to reset and clear the content?