Who doesn't love a good beauty hack? Gigi Hadid uses the age-old toothpaste-as-pimple-cream trick, Lauren Conrad de-puffs her eyes with raw potato slices, and we have a few favorites of our own, too.So when we heard that blogger Farah Dhukai recently posted a wallet-friendly trick to banish dandruff, we were, err...itching to learn more. Her weapon of choice? Original Listerine. That’s right, mouthwash.Dhukai claims that the antiseptics we use to de-yuck our teeth and gums can also banish dandruff in an instant. After diluting mouthwash with water and spraying it on her scalp, the blogger allows the solution to seep in for a few minutes before rinsing. “Listerine has menthol, thymol, eucalyptol, and methyl salicylate — all [of] which make it an antifungal, antiseptic, and anti-inflammatory, and PERFECT for getting rid of dandruff,” she wrote on her Instagram video.Hold up. You mean we’ve been sleeping on a dandruff solution that’s been plentifully stocked in our bathrooms this whole time? Naturally, we were equal parts dumbfounded and apprehensive. It sounds too good to be true, right? To get to the bottom of this hack, we checked in with Manhattan dermatologist Francesca Fusco , MD.Dr. Fusco says that the concept of using mouthwash on hair isn’t new — she’s even seen people use the stuff in an effort to spur hair growth. She understands the logic that drives these DIYs. “I guess they think that mouthwash would ‘kill’ any germs that colonize the scalp,” she says. But that isn't exactly what happens.“There is no scientific data to support this. Dandruff is caused by an overgrowth of yeast, and is often accompanied by a compromised skin barrier,” Dr. Fusco says. “I'd worry that use of a strong alcohol-based mouthwash could further disrupt the skin barrier on the scalp and exacerbate the dandruff.” She adds that the alcohol-rich solution could also have an adverse effect on color-treated hair.Instead of turning to the methyl salicylate and essential oils in mouthwash to de-flake our hair, we should turn to another active altogether: “The most effective way to combat dandruff is with a clinically proven shampoo-and-conditioner regimen with zinc pyrithione,” says the derm. Moral of the story? Stick to actual anti-dandruff products So while we may not be trying the mouthwash-on-the-scalp trick anytime soon, that doesn't mean all hacks should be cast aside. Neosporin as a zit zapper ? That trick, we’re keeping.