The question How do you moderate the moderators? Sounds to me more like it's asking how to set up a system of moderation than how to act as a moderator.
Let's say a question like:
"I have a review queue for moderators to review new posts on my forum. How do I encourage the moderators of my forum to use it?"
Provided it's not about making the UI better, where it would fit into the User Experience site, are questions about setting up, or the design of, a moderation system on-topic here?