Democratic President Joe Biden's campaign issued a stark warning for American voters as the President marked the fourth anniversary of former Republican President Donald Trump suggesting Americans could inject bleach "inside" to kill COVID-19.

Before the availability of effective COVID-19 vaccines and when Americans were under strict orders to quarantine to control the raging virus, Trump famously issued an off-the-cuff remark suggesting that a household disinfectant could be used to kill the disease.

“I see the disinfectant, which knocks it out in a minute," said Trump at an April 2020 news briefing, adding:

"Is there a way we can do something like that? By injection inside, almost a cleaning.”

On Tuesday, the Biden-Harris team shared a throwback clip of the news conference that sent federal and state agencies and bleach manufacturers scrambling to warn people against the ex-President's wink and a nod to the false and unsafe remedy.

"Four years ago today, Trump told Americans to inject bleach on national television," read the clip's caption.

Hours later, Biden shared the clip and trolled Trump by reminding voters:

"Don’t inject bleach."

"And don’t vote for the guy who told you to inject bleach."

It was Team Biden for the win.

Trump faced backlash for his April 2020 bleach comment, which followed his suggestion that medical experts should study exposing the human body to heat and light as a treatment for the disease.

His remarks were in response to a presentation by a top science official from the Department of Homeland Security sharing research that bleach and isopropyl alcohol could kill the virus within minutes.

“So, supposing we hit the body with a tremendous—whether it’s ultraviolet or just very powerful light—and I think you said that hasn’t been checked but you’re going to test it,” Trump said.

He added:

“And then I said, supposing you brought the light inside of the body, which you can do either through the skin or in some other way."

"And I think you said you’re going to test that too. Sounds interesting.”

Trump then asked if there were methods through which disinfectants could be used " by injection inside or almost a cleaning.”

Earlier on Tuesday, the Biden-Harris team posted another clip with Trump's comments leading up to the "disinfectant" musings focusing on the reactions of Deborah Birx, who was part of the White House Coronavirus Task Force from February 2020 to January 2021.

The next day, health officials, federal lawmakers, and the Consumer Product Safety Commission urged Americans not to use household cleaning products as a COVID cure.

Surgeon General Jerome Adams wrote on X (formerly Twitter):

“A reminder to all Americans- PLEASE always talk to your health provider first before administering any treatment/ medication to yourself or a loved one."

"Your safety is paramount, and doctors and nurses are have years of training to recommend what’s safe and effective."

The Food and Drug Administration also responded by warning that using the anti-malarial drugs hydroxychloroquine and chloroquine as a therapeutic, as previously touted by Trump, could have potentially lethal side effects.

On Wednesday at a construction worker's event in Washington, Biden jabbed Trump again for his improvised coronavirus panacea.

He said of his likely presidential challenger:

"Remember when he was trying to deal with Covid... He suggested just inject a little bleach in your veins

"He missed, it all went to his hair!"

Keep fighting the good fight, Dark Brandon.