bug 665084: Revised SQL to anonymize a production DB clone

This is not the total fix to bug 665084 (and in turn bug 802203), but I think it's a first step.

However, I'm not currently able to ssh into a production machine to grab a DB dump to try this out on. While I figure that out, I'm submitting this PR to get eyes on it.

IMPORTANT: Do not run this on production. Do not run this on anything important. It deletes data like crazy. It's meant to be run on a clone of a production DB, a dump of which will be intended for staging and dev boxes.