The actor was forced to spend three hours in the make-up chair every day to portray the Greek demigod, and the process got him thinking about what exactly was being put on his face.
He explained on "Live With Kelly & Michael," "The beard hair... had to be put on, strips cut, inch high, quarter inch wide, piece by piece. I asked my Italian designer, I said, 'Matteo, what is this?' He goes, 'Oh, it's the hair from a yak'. It's very expensive, very fine hair... He was putting it on my face and I go, 'Well, what part (of the yak)?' and he goes, 'The testicles!'"
So was he grossed out by the experience? Johnson added, "It's the softest!"
The film, directed by Brett Ratner, centers on Hercules, who has become a mercenary and is enlisted to help fight a savage warlord. It opens in theaters July 25.