Kayla Nicole knows how to sell hair products -- exchanging her clothes for a bikini and getting drenched in water for a jaw-dropping ad with Rihanna's Fenty Hair line.

The influencer/model/Travis Kelce's ex shared the clip on her social media page on Wednesday afternoon ... and it's quite the marketing tactic.

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The 33-year-old understood the assignment and immediately attracted the attention of her followers -- including Cameron Brink, who let out a "Sheeshhhh!!!!!😍" in the comments.

RiRi also showed off the same product earlier this week ... and in similar fashion, she put her stunning figure on display as well.

It's quite a busy time in Kayla's life -- she found herself in New Orleans two weeks ago celebrating the Eagles' Super Bowl victory over Kelce's Kansas City Chiefs ... which gave off hater vibes.

After this post, though ... who cares??

Of course, Kelce is now happy with Taylor Swift ... but even he would have to give Kayla's ad a 10 out of 10 (although we take it he'd never admit it).