Just to note, there's an easier way to run a custom build on multiple bots: go to http://buildbot.python.org/all/builders/ and scroll (way) down to the section for forcing a build on custom builders (you can search for 'Repo path:' (with the colon)), check the box next to all the builders you want, then fill out the Repo path, your name, reason, and revision.  You can also force the build on *all* custom builders; search for the second hit on 'Repo path:'.

...might not hurt if we document that somewhere.