10 Surprising Second Uses for an Onion

Onions can do a lot more than add flavor to foods. Check out these ways to use onions to clean stains, remove age spots from skin, repel bugs, and seven other surprising uses.

Bruce and Jeanne Lubin
3-minute read

Remove Rust from a Knife

Believe or not, the enzymes in onions will remove rust from metal objects! If you have a rusty kitchen knife, just plunge it into the biggest onion you can find, let it sit for a few seconds, then pull it out. Repeat this process until the rust has dissolved, then wash as usual and dry.

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DIY Stain Remover

Who knew that onions can remove stains? Two types of stains we have had success removing with onion juice are ink and scorch marks from an iron. If you have a particularly fresh and juicy onion, you can simply cut it in half and rub the cut end on the stain. Otherwise, grate it into a bowl using a cheese grater, then rub the stain with the grated onion, blotting it with as much of the onion juice as you can. Let the clothes sit for 8–10 minutes, and if necessary, re-apply the onion juice. Once the ink stain or scorch mark is gone, launder as usual. (If you’re battling a stain that’s not made from ink or a scorch, see our Stain Removal Guide.)

Ease the Pain of a Bee Sting

If you’ve been stung by a bee, onions can help. After removing the stinger and washing the area, apply the cut side of an onion half on the area. It should help ease the pain.

Revitalize Thinning Hair

One of the most incredible attributes of onions is that they’re loaded with sulfur, which can boost blood flow to your hair follicles when applied to the skin. To create a scalp treatment, you’ll first need to extract the juice: Peel an onion, then cut it into two to four chunks. Process in a blender or grate by hand, and strain out the juice. (Or simply use a juicer and clean it thoroughly afterward!) Massage the onion juice into your scalp and leave for 10–15 minutes…if the stink is overpowering, cover your head with a shower cap. Rinse with warm water and then shampoo and condition as usual.

Make Age Spots on Skin Disappear

This DIY beauty treatment is a little stinky, but it sure helps with age spots and other blemishes. Grate half on an onion, then squeeze out the juice in a small bowl. Mix in 2 teaspoons of white vinegar and 1 tablespoons of hydrogen peroxide. Dab a little onto unwanted spots each morning and evening and they’ll begin to fade within weeks!

Get Rid of Corns

Another great way that onions can help your skin is by eliminating corns. Make an onion compress by soaking a slice of onion in apple cider vinegar for a few hours. Remove it and place the onion over the corn, covering with a bandage. Put on cotton socks to protect the area and leave overnight. Repeat each night until the corn is gone.

Onion for Earaches

Oil found in raw onion is antimicrobial, which means that onions may help ease the symptoms of everyday respiratory ailments. One home onion remedy that has always been used in our family is for earaches. If you have a minor earache, slice a fresh onion and heat it in the microwave on high for one minute. Wrap it in cheesecloth or another thin cloth so that it doesn’t burn your skin, and then hold it against the ailing ear for 20–30 minutes. Make sure to see a doctor if the pain gets worse or continues for longer than 24 hours.

Keep Bugs Away from Plants

Humans aren’t the only ones who hate the smell of onions. If aphids or other bugs are eating the plants in your garden, onions can keep them out. Chop up an onion, place it in a cup of water, and puree it until it’s liquid. Pour the concoction into a plastic spray bottle and use it to mist the plants that are being eaten. For best results, try it at dawn before the sun starts blazing.

Get Rid of Household Odors

Onions can actually neutralize strong odors in the air. Just slice up an onion and put it in a stinky room or closet, then throw away a few hours later. They’re especially good at absorbing the smell of paint in a newly painted room, and absorbing a mildewy smell in a basement or garage.

Onion Grill Cleaner

One of our favorite barbecue hacks ever is using an onion as a grill cleaner. It helps reduce smoke and improves the flavor of food on your grill, and it’s perfect for public grills in parks! Just cut a red onion in half, pierce it with a fork, and dip in water. Then use the onion half to wipe down the grill rack once it’s hot. The onion’s enzymes will break down grime, and its antimicrobial properties will help disinfect it.

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Photo by Shutterstock.

About the Author

Bruce and Jeanne Lubin

Bruce Lubin and Jeanne Bossolina-Lubin are the proud parents of three boys and more than a dozen books. After saving thousands per year using everyday tips and simple lifehacks, they started their own business in the hopes of sharing their knowledge with others. They have been known to go into their friends' refrigerators to turn their eggs upside down so that they last longer.