That's going to become pretty important over the next few months as we all think of ways we can minimise the possibility of contracting anything which remotely looks like coronavirus. So I hung around a bathroom in a public place this week just to observe what people did.

There are those who turn the tap on and wiggle their fingers underneath the flow, fling their droplets everywhere and then wipe their hands down the sides of their clothes. There are some who make a direct exit from cubicle to the door. Some use soap but only wash one surface of their hands. Others are more thorough - palms, top of the hands, between the fingers, using plenty of soap and water.

These are Ramon Shaban's people. He would love every single Australian to follow the 30 second rule, using plenty of clean running water, soap and a paper towel.

Professor Shaban is an infection-prevention and disease control expert at the University of Sydney, and says that we should all avoid hand blow-dryers at all cost. They are just disease spreaders.

This completely horrified me. I thought those gadgets were the bee's knees of hand-drying excellence. Turns out they are the complete opposite.

READ MORE:

The hand blow-dryer "aerosolises" droplets, taking whatever moisture you have on your hands and then blowing it around at a zillion knots. That might be entertaining if everyone is healthy, but then it depends what you have on your hands.

"If I've got influenza A and I wash my hands but I'm coughing, using the hand-dryer blows those droplets onto anyone else in the room ... the dryers create a windstorm of droplets," Shaban says.

Turns out, they are not used in hospitals. Shaban explains they are unauthorised, equipment which is not permitted in a hospital setting. Paper towels are the go, and if you don't have those even the sides of your clothes are a better option.

"If you've got nothing else, then your clothes are OK, because you don't want to open a toilet door with wet hands. A dry hand is better than a wet hand."

Actually, there really are three kinds of hand-washers, or at least three kinds of hand-washing: social, clinical and surgical. Social is what the broad community does (or should do); clinical is a little more robust, using an antibacterial agent and taking a longer time; surgical is what doctors and nurses must do before they open you up. They have to be "bare beneath the elbows" to make sure they get every little crevice clean and dry, then it's five minutes of washing with chemicals and then sterile paper for drying.

Why does hand-washing matter?

Shaban gives a shout-out to Ignaz Semmelweis and to Florence Nightingale, who both recognised that if health workers washed their hands between patients, fewer patients would die. That turns out to be true for all the steps before death, too. Hand-washing works because it breaks the chain of infection, which basically works this way:

Someone's sick, they leave a little droplet on a surface somewhere or cough and don't cover their mouth. Those droplets are just hanging out in the air waiting to land on someone. Maybe you touch a door handle, and then touch your mouth or ears. You've been a little off-colour anyway... then BAM.

Or, you are robust and resplendent, and the infection never puts its claws into you. So, in between hand-washing, remember to cough into your elbow, people. Shaban says Australians aren't too bad overall when it comes to public health initiatives - for example, we are excellent with immunisation.

But he was a little unsure about why rates of sexually transmitted infections have spiked in Canberra; and no, STIs are not preventable by hand-washing because, oh god, for all the reasons. It's a whole other public health process.

"The burden of disease in any area of health is a complex set of interactions and factors, and it's no different in sexual health," says Tim Bavington, executive director of Sexual Health and Family Planning ACT.

Basically, while using condoms is great for preventing pregnancy, transmission of HIV and other STIs, it's no longer a highly valued form of contraception.

Still a bit of a way to go for this public health challenge.