This is a great post. I have participated in a campaign like this using preprinted materials revealing true information about vaccines created by learntherisk.org. The materials include postcards and sticky notes. I had hoped to share a link to some of these resources, but apparently this information is now heavily censored.
Unfortunately, the web site for learntherisk.org has become inaccessible to me via the contemptible search engines known as go-ogle and "dud-dud-stop". (Sorry I am a little "irritated" by this.)
Chain of unchristian expletives later. I would just like to say that I think this idea is excellent. I have plain sticky notes suitable for this purpose.