Jennifer Lawrence was taught how to mop by her Joy co-star Bradley Cooper.

The Oscar-winning actress plays Joy Mangano, the woman who invented the Miracle Mop, in the real life rags-to-riches tale opposite Bradley, who plays an executive at the Home Shopping Network helping the aspiring entrepreneur get her brand off the ground.

Jennifer admits she learned her cleaning skills from her mother, but did not know how to mop properly until she started work on the film.

Bradley was left aghast when he saw his longtime collaborator's terrible floor-cleaning, so he taught her the tricks he learned with his own Miracle Mop.

"You have to understand my mom was OCD (obsessive compulsive disorder) so I had to clean my room and do laundry and clean my dishes, but I don't think my mom would ever let a morsel of food get on the floor without bleaching the whole thing," she says.

"Bradley's mom bought everything from (shopping network) QVC, and he had a Miracle Mop in his dorm room in college so he watched me mop in one scene and was like, 'Dude, no!" and showed me a better way."

During the interview, published on Smh.com.au, Jennifer reveals she spent hours watching the real life Joy show off her products on TV in old episodes, and she became obsessed with her inventions.

"Joy's mind is endlessly fascinating, and she still has hundreds of ideas for inventions!" she adds. "I was so impressed with her inventions that I actually tried to buy one until my friend reminded me I'd recorded the shows and it doesn't work if it's not live!"