Turns out, mouthwash has a purpose outside the bathroom.

I’m a big fan of fresh-cut flowers. While others look forward to their Trader Joe’s runs to pick up the newest, hottest item or their favorite pre-made salads (chicken Caesar, thank you), I make a beeline for the floral display to grab an armful of cut blooms to take home and arrange.

I always plan my TJ’s trips first thing in the morning to get the freshest flowers available, and once I’m there, I decide on the color palette for the week since I like my arrangements to be monochromatic. If I’m lucky, they have gladiolus—a bloom that always has a standing invitation in my kitchen, but I’m open to any flowers that catch my eye otherwise.

When I heard about the technique of adding mouthwash to cut flowers to keep them fresh, I decided to give it a try. All you do is add a capful of alcohol-free mouthwash to the water in your vase before adding your flowers, and it supposedly makes your bouquet last longer.

Happy for an excuse to go to Trader Joe’s for some fresh stems, I picked up an assortment of yellow blooms, including double peony tulips, roses, gerbera daisies, and regular tulips. I took home some white ranunculus for a bit of contrast and some adorable yellow and white chamomile for a dainty accent. I also got some pink gladiolus for my kitchen counter.

Why mouthwash? The anti-bacterial properties that keep your breath fresh also keeps your cut flowers fresh, too. If you’ve ever noticed the water in your vase turning cloudy or even developing an unappealing odor, it’s the result of bacteria growing around the base of the stems, which then become choked and unable to take in nourishment from the water. (Tip: Strip the leaves off your flower stems to eliminate possible contamination and cut the bases to open them up to receive water instead of just taking off the cellophane wrap and plunking them into a vase.)

I created two arrangements of the exact same flowers, down to the number of stems, and waited to see the results. And it’s true, the mouthwash-treated flowers do look fresher and healthier four days in, especially the delicate chamomile, though there isn’t a major difference.

But after investing in pretty blossoms, I’m happy to do whatever I can to help them last as long as possible. I’ll be adding mouthwash to my cut floral arrangements from now on—maybe Trader Joe’s should be displaying it alongside their floral selection? I’d say that’s a clever idea.