Why do we need to wash our hands for 20 seconds?

Simply, the corona has a fatty sticky outer layer which means it sticks very easily to any surface.  Soap has a compound which dissolves the fatty layer and the corona either falls off the surface or is killed. 

It is important that the soap is rubbed into your hands long enough to create a lot of lather, which should then be rubbed over the whole of your hands for 20 seconds to kill all the coronas’ or the rubbing knocks them off. 

But your hands have many surfaces and parts to clean individually, and the lather needs to cover all of them to capture the germs within—palms, wrinkles, fingernails, between fingers, under rings, bandaids, or splints you may have on an injured finger. If you are doing it right, 20 seconds allows for enough time to be thorough, and for soap molecules to do their job on the entire hand.

The use of sanitiser will only work if it contains 70% alcohol.  We touch our face with our hands between every 2 and 5 minutes. 

The following link is very interesting……………
https://www.sciencefocus.com/news/coronavirus-can-hand-washing-really-stop-the-spread-of-covid-19/