This got my attention because my own dentist has made all patients gargle with mouthwash for 30 seconds before hopping into the chair since the pandemic began. And why not? It’s not crazy to think the comparatively harsh chemicals in the solution might neutralize fragile viral particles in the mouth and throat. If you’re a dental professional with a dozen or more people breathing in your face each day while COVID is rampant, you’ll try everything you can think of to reduce your risk of exposure.

Of course, people also breathe through their noses, where viral particles also reside. Mouthwash isn’t going to help with that. But we needn’t let the perfect be the enemy of the good.

I laughed at what one epidemiologist told WaPo about RonJohn’s recommendation. Is it worth using mouthwash, he was asked? Absolutely, he said — as long as you’re also vaccinated. “That way, one would be at reduced risk for infection and have good smelling breath.”

JUST NOW: Ron Johnson, on a Wisconsin tele-town hall, pushes mouthwash as a COVID treatment.

"By the way, standard gargle, mouthwash, has been proven to kill the coronavirus. If you get it, you may reduce viral replication. Why not try all these things?" pic.twitter.com/V0cdxPYc7K

— Heartland Signal (@HeartlandSignal) December 8, 2021

There actually is some science behind this idea. An in vitro study found that certain types of mouthwash (not all) are highly effective at killing SARS-CoV-2 particles — like, 99.99 percent effective. Whether they’d be equally effective in a person’s mouth and throat is unclear, but a second study claimed that patients already infected with COVID who rinsed with mouthwash had fewer viral particles in their mouths afterward than patients who rinsed with a placebo did.

Bottom line: It can’t hurt and it might help. Johnson insists he’s getting a bad rap from reporters who are dunking on him over this today, and he has a point.

Ron Johnson tells @tedbarrettcnn his covid-mouthwash remark taken out of context. “I’m doing a telephone town hall and I'm telling people take it seriously and do what you can to boost your immune system and eat healthy…I was just trying to tell Wisconsinites to take it serious”

— Manu Raju (@mkraju) December 9, 2021

The problem with having RonJohn recommend mouthwash is that his advice is likely to be taken as a substitute for vaccination among his target audience, not a supplement to it. He’s sounded skeptical about the vaccines before, after all. As a populist Republican he must know that the sort of person who’s eager for ideas about “alternative” treatments for COVID typically is looking for reasons to avoid getting their shots.

If someone gets vaxxed and then wants to “enhance” their protection by using hydroxychloroquine or ivermectin or Listerine, well, what’s the harm? But if they’re using those treatments in lieu of vaccination, there is harm. Harm to themselves in the form of higher risk of a bad outcome, harm to the community by eschewing a precaution that would reduce their chances of passing the virus on to others.

Though mouthwash can partially kill off parts of the coronavirus in a person’s mouth, most infections occur through the nose, health experts said. “Even if gargling kills some of the virus, it won’t be able to clean the nasal area, nor the viruses that’s already penetrated deeper into the body,” said Kim Woo-Joo, an infectious-disease expert at Korea University.

“We’re looking at how [mouthwash] actually works on the virus itself rather than what it does to the body. I think those are two separate questions,” Nicholas Rowan, an ear, nose and throat surgeon and assistant professor at Johns Hopkins Medicine, told The Washington Post last year.

Listerine has gone as far as to set up a webpage tracking studies on mouthwash and COVID and warning readers that the evidence of efficacy is thin so far, especially in studies involving infected people. Normally it’d be insane for a company to try to disabuse consumers of their belief that its product works against a killer virus but I’m sure management also fears the “substitute, not supplement” logic at work. Those who are, ahem, doing their own research on mouthwash and COVID are doing it because they’re looking for excuses not to get vaccinated. Listerine doesn’t want to give them any.

The irony of Johnson recommending mouthwash as a treatment for COVID is that, to the extent it does work, one would think it works mainly to prevent the user from infecting others rather than to prevent them from being infected. If you’ve been out socializing and fear that you may have inhaled some viral particles, I suppose you could try using mouthwash when you get home to try to kill those particles before they begin replicating. But realistically, using mouthwash would make more sense *before* you go out socializing, to kill any particles in your mouth that might already be there so that you don’t go ejecting them into the airspace of other people. (Hence the reason dentists want patients to use it.) That’s ironic because the rationale for wearing masks, which righty populists like Johnson generally despise, is similar. The value of masks lies in limiting the number of particles ejected into the air by the wearer by catching them at the source; you wear the mask to protect others more so than to protect yourself. Mouthwash works the same way, yet here’s RonJohn embracing it.

Or is he? Does he mean to suggest that people should be using mouthwash to protect themselves from being infected? Does he want people to gargle every time they have a conversation with another person?