The Italian actress plays a prostitute in "The American", the new film which stars George as an assassin.
Asked whether Clooney helped put her at ease, Placido said: "Absolutely. There was a good atmosphere of trust. We could focus a lot. There was concentration."
The 34-year-old actress added: "It wasn't my first time (stripping in front of the camera). I remember my first time was tougher, but I think that once you get into this, you decide to become an actor and you explore everything of human aspects through different roles all the time."
"When we tell the story, there is the body that talks sometimes. An actor is ready to be naked in all senses with emotions and with its body. I don't see much difference."
She added: "When you're trying to tell a character and in this case, the character is a prostitute, then the body would come in. It would be very unnatural if you tried to hide that part, and not tell the story through the body as well."