How can i ask someone to review their product?

Okay, on youtube, there are many guru's that review products. LIke people send stuff to them to make a video on youtube for the product. i would love to ask this one women to review her products by sending me some for free. how can i ask her without sounding rude? i really would like to make a youtube video on the stuff, but how can i ask her? no mean answers, thanks!