I don't think you grasp what libchamp was proposing. He's saying experts in various fields create a thread where people can ask questions relevant to the OP's expertise. For me, this would be something like:
Thread title: Ask a chemist
Questions could be like "how do I measure the pH of my poolwater," or "wtf is this growing on my battery terminal?"
It would be useful because people are more likely to ask questions if they think someone knowledgeable is listening.
I think it's a great idea. I might even create the thread above if it comes into being.
We'd have to keep liability issues in mind. I'm not sure the best way that should be handled. Disclaimers listed on the bottom of the first post?