Couldn't you just create an account for them that has a few whitelisted posts that are squeaky clean? Or better yet apply the whitelist when a request is made from a not-yet-released version of the app, based on headers?
Secretly giving Apple’s reviewers a different version of the app is a very good way to get them really upset at you. (And, IMO, rightfully so: you’re no longer acting in good faith. They might not be either, but when you’ve changed your position you lose the ability to make the “we tried our best to be reasonable” argument.)