The actor - who starred as Paolo Gucci, vice president of the fashion brand, in the new movie - has claimed he was so dedicated to the role he got up close and personal with some stereotypical Italian food.
He said, "I did it all. I was snorting lines of arrabbiata sauce by the middle of this movie. I had olive oil for blood. This was a deep dive I did. If you took a biopsy of my skin, it would come back as parmesan cheese! This is my love letter to Italy."
"There was a lot of work and preparation, and yes, I had an Italian accent, and I enjoyed and embraced that and lived in that space as much as I could, and for as long as I possibly could. I climbed into that creative cave and came out through the bowels and intestines into the oesophagus of the one and only Paolo Gucci."
The 30 Seconds to Mars frontman also went on to detail how his "butt was shaking" on set, claiming that playing the character, who becomes embroiled in the murder of Maurizio Gucci, was like "giving birth to a bowling ball."
He told I-D Vice, "Bringing Paolo to life was like birthing a bowling ball out of my sphincter."
"I keep saying my butt was shaking like two little chicken bones on that set. It was a very physical performance. There's something about corduroy, I think: when you put it on, it's like you can catch fire."
It comes after his co-star Lady Gaga told how in preparation for her role as Patrizia Reggiani - who was convicted of hiring a hitman to kill her ex-husband, Gucci founder Maurizio - she studied a variety of animals.
She said, "I studied animals, actually, for this, I studied a house cat, a fox, and a panther."
"I studied the way they seduced. The way they hunted. The way they would produce. The way they would enjoy themselves."