How to programmatically umount filesystems mounted by autofs?

I have some RHEL systems where I need to disable autofs. What I typically do is run a script on each of these hosts that executes something like this:

# /etc/init.d/autofs stop
...
# /sbin/chkconfig autofs off
...
# reboot

But I have a situation where doing the reboot will cause a problem. I guess I could log on to each of these hosts one-by-one and execute df and seem what filesystems where mounted by autofs and execute by hand umount /whatever but that would be a pain. Does anyone know of a slick way of shutting off autofs and umounting the filesystems it mounted?

I do have access to puppet. Maybe it would be possible for me to use puppet to edit autofs's config files and then service autofs reload?

Thanks