(CNN) It's the pandemic mantra: Wash your hands -- often.
Do it with lots of soapy bubbles, scrubbing for a full 20 seconds (or the time it takes to sing "Happy Birthday" twice). Rinse, dry and repeat as often as possible.
And we did. A June 2020 study by the US Centers for Disease Control and Prevention found Americans said they were lathering up twice as often as they did in 2019.
In one Chicago hospital where the use of soap and sanitizer is electronically tracked 24/7 via every room entrance and exit, a new study found staff were 100% compliant just after the virus invaded our shores -- much to the delight of infection control specialist Dr. Emily Landon.
"Our health care workers were really worried about Covid -- they didn't know who had Covid and who didn't -- so they were extremely careful with their hand hygiene," said study coauthor Landon, executive medical director of infection prevention and control for University of Chicago Medicine.
Unfortunately, it seems we've all quickly gone back to our old habits.
It only took four months for doctors, nurses, techs and cleaning staff to drop back to a 51.5% daily handwashing compliance rate, according to the study published Monday in JAMA Internal Medicine.
And a nationally representative survey done in January found only 57% of Americans said they were washing their hands six or more times a day -- such as after using the bathroom, before eating or after returning from a trip outside the home.
That's a significant drop from the 78% of people who said they were washing hands frequently when the survey was conducted in the early days of the pandemic.
"Hand hygiene is a habit. It's like wearing your seatbelt, or eating healthy or exercising regularly; it's something you have to get used to doing," Landon said.
Let's face it -- studies find we don't regularly wash the nasties off our hands even when we know we should. And if asked, we even lie about it.
"None of us wants to be seen as dirty, so we're willing to lie that we washed our hands after we went to the bathroom," Landon said.
Women are more likely to lie out of embarrassment than men, who typically "really don't care" whether they wash their hands, said Jon Dommisse, director of strategy and corporate development for the Bradley Corporation, a commercial bathroom fixture company that conducts regular nationally representative surveys of America's handwashing habits.
The CDC reports backs that up: "Regardless of year, men were significantly less likely than were women to remember to wash hands before eating at a restaurant, before preparing food, after using the bathroom at home, and after experiencing respiratory symptoms."
Men got with the program a bit more last year after the Covid-19 pandemic began, Dommisse said.
"It's like a battle of the sexes as to who washes their hands more," Dommisse said. "Every single year women beat men, except for this last year of Covid men seem to be more attuned to keeping better habits. It was kind of shocking."
But by January, only 38% of Americans were continuing to remind family members to wash their hands, compared to 54% last year, Dommisse said, while "rinse and runs" were on the rise.
"We call it the 'rinse and run' where you go into a public bathroom and don't take the time to use the soap -- you just rinse your hands and run out the door," he said. "In April 2020, only 27% admitted to doing that. In January of this year, it was up to 48%."
The good news is that we can learn healthy hand hygiene habits again -- as shown over the dozen years that Bradley has been surveying Americans' handwashing.
"Every time that there's some type of flu or health outbreak, it definitely escalates," Dommisse said. "Obviously it happened with with Covid -- they're the highest ever -- but we saw improvements with SARS, Ebola, bird flu, even a year when just regular flu was much more prevalent."
While it may be shocking to learn that hospital staff might have dropped in hand hygiene compliance, keep in mind that the new study was monitoring each room and hallway they entered, not just bathrooms.
That's because within about 24 hours after a patient is admitted to a hospital room, the entire room is covered in "a patina of their own bacteria, just like your home is covered in your bacteria," Landon said.
"And if you don't clean your hands, then you bring that out to the nursing space, then you can bring it into another patient's room," she added. "So we expect everyone to clean their hands twice for every time they go into a room, once on the way in, once on the way out."
If doctors, nurses and techs "bunch" their patient duties together, they can enter a room much less often, which is what the study found in the early days of the pandemic. But as time went on, staff regressed to dropping in and out to check on their patients, Landon said.
"It may be a little bit of a shock to most Americans that some doctors and nurses are not cleaning their hands," she said, "but it's because of all those sort of quick in and outs that we often do.
"The reality is that when hospitals look at their hand hygiene in a comprehensive way, where they measure every single hand hygiene event that is supposed to happen, they often find that they're running about 30% compliance," she said. "So our 51.5% is actually quite good."
It's really not that hard to have clean hands, experts say.
"Set up some rules for yourself," said infectious disease specialist Landon.
"If you show up at my house, the first thing I say is, 'Hey, take your shoes off and would you mind washing your hands?' Our house rules are we wash our hands before we eat, we wash our hands after going to the bathroom, and we wash our hands when we come inside from an activity, such as going into work or returning home."
There's a proper way to wash your hands -- a full 20 seconds, with lather, scrubbing inside fingers and fingertips and backs of hands. Here's a video by CNN Chief Medical Correspondent Dr. Sanjay Gupta that can show you how.
Perhaps you already feel that you are doing your best to wash up, the right way? Landon hears that all the time from patients who have Covid and say, "I did everything right. I followed all the rules."
"When you talk to them it turns out they've been cutting some corners," she said. "So, chances are if our health care workers are cutting corners with cleaning their hands in the hospital, then you're probably cutting the corners with cleaning your hands at home, too.
"It's probably time to put a little bit of extra effort back into that," she said.