Mel Gibson uses a smelly ointment made from cow's brains to sharpen his mind for poker games with pals.
The movie star and his publicist Alan Nierob invited Up In The Air author Walter Kirn to join them for a card showdown as part of an article for U.S. magazine Men's Journal - and Gibson insisted on smearing the goo all over his arms before the first hand was dealt.
The actor told Kirn the substance, called Selegiline, helps to clean "the neurotransmitters," but Nierob insists the ointment doesn't help his client and friend win - Gibson's a "loser" whose losses have helped put the publicist's kids through college.
Kirn later discovers that Selegiline is actually used to "treat Parkinson's disease and alleviate depression".