Log out users programmatically?

I’m continuing work on scripts for a dev/prod MODx setup... that is, we have a fully functional, complete copy of our site on a dev server, then we move it to prod. However, it’s best if we can ensure that all users are logged out of production before we push out a new update. Is there any way to do this cleanly? If I shut down the mysqld, and restart apache to point to a new DocumentRoot (e.g. a root that displays a "We’re doing Maintenance" page), then that prevents users from logging in while updates are occurring, but that’s not a clean way of doing it. Is there a better way?

Many thanks!

Ok... that’s marginally better... but I need something to run via a bash script.