Skeptic Project

Better idea:

Just don't talk about this shit with your dad.

Problem solved.

http://en.wikipedia.org/wiki/List_of_cognitive_biases Some of these might explain why he latches on to irrational beliefs and is unable to shake them. If he is open to learning about them, he might start noticing the biases within himself, which may cause him to question his beliefs and maybe even change them. Learning about cognitive biases and logically fallacies is how I made my way away from woo and conspiracy theories, but I'm sure it doesn't work for everybody. Just an idea.

Confirmation bias is probably the most important one when it comes to conspiracy theories.