"But it's only sticky at the top, it's not sticky the whole way. It would also come off because the adhesive would wear out, so then they would superglue it to my body so that it wouldn't fall off. And I would wear two of them."
The actress said that while the strapless thongs weren't uncomfortable, she did find it to be a "bizarre" experience.
"It's not painful. I mean, it's barely anything. But I guess you have some sense of being covered. It's f**king bizarre," she said.
The final film in the series focuses on newlyweds Christian Grey (Jamie Dornan) and Anastasia Steele (Johnson) as they try and move on from their past.
However, as Anastasia steps into her role as Mrs. Grey, Christian relaxes into an unfamiliar stability, which could threaten their relationship.