When they found out hand-washing was effective in improving health and stopping the spread of bacteria, how did they convince the whole world?

Question

I’m sure many people were skeptical about this, like how people are now with vaccines. But how did this seemingly common knowledge spread around the world enough that people were convinced it was true?

In: Biology

Answer 1

It came before germs etc were understood.

So people then said- if I can see my hands are clean (after washing with soap and water), then they are clean.

And they thought ‘unclean’ lead to ill.