The 62-year-old Oscar-winning actress - who plays Grace Botempo, a whorehouse madam, in her new film `Love Ranch` - thinks actors do the opposite of what women working in the sex industry do, but still have to use their assets to get work.
She explained: "The girls who work in the sex industry, they put themselves out of their bodies. An actor does sort of the opposite. People say `Oh, you play someone else.` I`m always playing myself. You can only do it by going into yourself, in the deepest, most terrifying way.
"Not to say I haven`t ever prostituted myself quite often and happily. But in my heart it`s very serious."
The British star - whose husband Taylor Hackford directed her new movie - loved working on the film because she got to act out her secret dream to be a "bad girl".
She explained to New York magazine: "It`s amazing how quickly you get into dildos everywhere and pink-feather handcuffs. Within an hour you`re completely used to it.
"I`m still the good girl who wants to be a bad girl. But I`ll never make it as a bad girl - I`m not a prude or a moralist and I never have been, but I`m too fearful, too much of a wimp, really."