I’d link to the offending post that’s been making the rounds, but you’ve likely already seen it, and I don’t want to give it any more clicks. In short: Oil pullers say “pulling” oil through your teeth and swishing it around in your mouth for 20 minutes daily will, among other things, result in whiter and stronger teeth and fewer cavities, alleviate gingivitis, provide headache and hangover relief, improve sleep, clear sinuses, get rid of skin conditions such as acne, eczema and psoriasis, relieve general pain, resolve hormonal issues and detoxify the body. Other sites have even claimed that it will help with migraines, arthritis, meningitis and heart disease.
I don’t mean to be a Debbie Downer here, but there is absolutely no scientific information that supports these claims aside from a few small studies in India that showed a positive relationship between oil pulling and reduced cavities and gingivitis. And that makes sense; coconut oil has some antibacterial and antimicrobial properties, so swishing it around in your mouth might possibly remove some harmful bacteria that causes cavities and gum disease. But the same thing can be done with mouthwash (for a much shorter time), vinegar and even water.
As for the whitening, I imagine that heavy coffee or wine drinkers would see an improvement in whiteness from rubbing coconut oil against their teeth for 20 minutes a day. However, brushing teeth with baking soda once a week for just a minute or so is much more beneficial. And cheaper. And more efficient.
There have been some studies about the benefits to skin, but when only when coconut oil is applied topically (I have personally used it topically for some skin issues and been happy with results). There’s no evidence to support any of the other claims of oil pulling, though. However, there have been theories that heart disease has a link to oral health, so that claim could be true, but it’s still pretty flimsy.
The flimsiest of all the claims is “detoxification.” Folks, detoxification of the body by some magic potion is a myth. If you want to detoxify, change your diet to a whole foods diet, drink at least 8-10 glasses of water a day and live in a purified air bubble. Cleanses are great for resetting your appetite and improving your mood by breaking a junk food cycle, but they don’t flush out toxins, either. That takes time and a lot of effort put into avoiding the intake of toxins.
On top of the bogus claims, using unrefined coconut oil as a mouthwash is a crime against food. The only thing worse is using a perfectly ripe avocado as a face mask. Why would you do that? Eat that damn avocado! Eat the coconut oil! It’s delicious! Aside from a toast spread, you can toss broccoli, Brussels sprouts, bok choy, or other vegetables in it for stir-frying or roasting (sesame oil — also popular among oil pullers — is also tasty used this way). Or just eat it by the spoonful (though in moderation; a tablespoon has just about all the fat you should consume in a day).
Just don’t waste it by using it as a mouthwash. Oil pulling isn't harmful or particularly helpful, but it is wasteful.