How do I clear the chat log?

I know of the setting button, but that is not relevant as far as I know. I need to clear the chat log for everyone so that player chat logs do not show my macro tests for the new monster abilities right when they sign in. I have a player account I use and signed in AFTER, as the GM, I cleared the chat log and the stupid macro tests were still there for the user. That's just silly! So how do you REALLY clear the chat logs?

Go to My Campaigns -> View Details -> Under the Campaign Icon there is a button that says "Clear Chat History". Click on that. Once you do it will be cleared...for all time... But the NSA will still remember...forever.