The 48-year-old actor plays journalist Paul Kemp in new movie `The Rum Diary` - based on the exploits of notorious writer Hunter S. Thompson - and he admits the scenes where he pours alcohol in his mouth and sets it alight wasn`t the first time he achieved the feat, recalling a "weird" experience when a friend had to save his life when a trick went wrong.
He said: "I did spew a little fire when I was a youth. I very dumbly chugged a little bit of gasoline and blew it into a torch and my head was on fire. That`s true.
"It`s a weird thing when your head is on fire. You tend to panic first. And then when panic sets in and you cannot get your face out, you run. Which is the worst thing you can do. A friend of mine, a guy named Bones, came over and put my face out. He saved my life."
Despite his scary childhood experience, Johnny was delighted to repeat the stunt in the movie.
He said: "I was very excited that night about the possibility of actually spewing fire."
And the `Pirates of the Caribbean` star would happily tackle the feat again.
Speaking at a press conference for `The Rum Diary` on Wednesday (12.10.11), he joked: "I`ll do it again for you today if you`d like."