We like to make life miserable for bacteria with warm water and soap. Preferably antibacterial soap. But that won’t kill every microbe. It is impossible to wash all bacteria from your hands. And that’s a good thing, according to experts.
Washing hands for thirty seconds prevents diseases

At the start of the coronavirus pandemic, we were told to wash our hands with soap and water for 20 seconds. According to the RIVM, this was sufficient to considerably reduce the risk of pathogen transfer. But those twenty seconds are still on the right side, according to other (infection) researchers. They recommend thirty seconds.
In any case, half a minute of washing is enough to get most of the so-called ‘transient bacteria’ off your hands. That’s often where pathogens are found. Transient bacteria are specimens from outside that come to your hand from the environment. For example, during a visit to the toilet. That’s why it’s so important to wash your hands for thirty seconds.
Your body’s own bacteria are your friends

What about all those other bacteria? Those are a lot harder to get rid of. In addition to transient microbes, that is, those from outside, you also have your own specimens. These are the so-called resident bacteria. And you can’t even get them off after washing for minutes, because they are deep in your skin. Fortunately, these bacteria are not harmful to you.
In fact, those harmless bacteria are even more than welcome. Precisely because they do us no harm, they are handy residents. Their presence means there is less room on your body for dangerous species. Our body is therefore happy with such benign inhabitants.

Watch out for chapped hands
There is another reason not to wash your hands too extensively: this will make your hands lose their oiliness. Dry hands are more porous, making it easier for dangerous bacteria to penetrate. It is not without reason that you get eczema from really dry hands.