Bethenny Frankel is always testing the latest beauty finds, but every once in a while, a product actually makes her stop and rave. Recently, she revealed that one particular hair treatment left her strands feeling "brand new": the viral K18 Leave-In Molecular Repair Hair Mask, a cult-favorite formula that's gained a massive following for its ability to revive dry, damaged hair in just minutes. Frankel shared the discovery with her followers on Instagram, swearing that the mask "reverses damages in four minutes.