Quoting Skeptical Science on debunking myths:
Common wisdom is that the more counter-arguments you provide, the more successful you’ll be in debunking a myth. It turns out that the opposite can be true. When it comes to refuting misinformation, less can be more. Debunks that offered three arguments, for example, are more successful in reducing the influence of misinformation, compared to debunks that offered twelve arguments which ended up reinforcing the myth.
For commentary on how scientists should respond to denialists, read Diethelm and McKee: Denialism: what is it and how should scientists respond?
Another interesting paper: Reber and Schwarz: Effects of Perceptual Fluency on Judgments of Truth