Is the Catholic church a force for good in the world? (Speaking for the motion, Archbishop John Onaiyekan and Anne Widdencombe MP. Speaking against the motion, Christopher Hitchens and Stephen Fry) CNN (Just fucking with you, this was on BBC WORLD NEWS not too long ago)
This was not an even match but there were hundreds of conversions at the end, therefore this format must be effective, even if it created new questions for those who were undecided at the end.
I think the idea of taking precious beliefs and crushing them without any remorse just to demonstrate how preposterous they are is quite the effective method. Also, C. Hitchens the eternal contrarian that he is (god save him), is a force to be reckoned with on the Mic. Mind you, not that any expert theologian of this era would have been any better than the Archbishop in a debate against him on this particular subject.
Watch it from the first one if you like a good debate.