Haha. I've already tried it with a couple of non-xRationalists with great success (read the life plan above); the problem is that a) I spent most of my brainstorming time explaining to them how and why they were making cognitive biases, and b) I don't know any rationalists in real life. I'm currently converting my older brother and his girlfriend.

We'll also need to do a double-blind control, with the brainstormers smoking something that seems like Cannabis but isn't psychoactive. Is there something like that? Maybe we could use ABV. A second control could also be useful, where the brainstormers don't smoke anything.

And, of course, we'll want as much data as possible. That means multiple groups conducting the experiment and reporting their findings. Like you said, it's inexpensive, so it shouldn't be too hard to get the experiment rolling so long as enough people are interested.

EDIT: The following is sort of irrelevant now, since people have begun giving me constructive criticism. I'm keeping it for posterity's sake.

EDIT: Please explain your downvotes. I was led to believe that this community was less susceptible to the follies of the representativeness heuristic (I'm assuming that is a large reason for the downvotes, given MixedNuts' first comment). Does it sound like the meta-belief of Cannabis held by uneducated, delusional hippies that the plant will cure all of the world's ills, and that is why you dismiss it? If you're not downvoting it just because it sounds like another pipe-dream made by a crazy stoner, then ask yourself why you're downvoting it. Examine why the reasoning is bad and then tell me why, please.

I'm quoting the Less Wrong introduction thread

However, it can feel really irritating to get downvoted, especially if one doesn't know why. It happens to all of us sometimes, and it's perfectly acceptable to ask for an explanation. (Sometimes it's the unwritten LW etiquette; we have different norms than other forums.) Take note when you're downvoted a lot on one topic, as it often means that several members of the community think you're missing an important point or making a mistake in reasoning— not just that they disagree with you! If you've any questions about karma or voting, please feel free to ask here.

It is very likely that it is not you, but me who is missing something. I would like to be elucidated.

EDIT2: I got my explanation, see above. I'm glad this will evolve into a discussion.