Those Dettol adverts truly annoy me, because what they are trying to achieve is simply to frighten people into buying their products. So they quote meaningless statistics ("one million germs per inch of kitchen table", "more germs on a dishcloth than on a toilet seat") and unfortunately lots of people are taken in. The worst thing is the way they target parents of babies, showing (shock, horror) a baby picking up a play brick from the floor and sticking it in its mouth.
What they choose to ignore is that we have an immune system which needs regular exposure to infectious organisms in order to build up and maintain its health. Without that exposure, the immune system gets weak and ineffective, just like a muscle which doesn't get exercise. People brought up in near-sterile conditions tend to have poor health and a high incidence of allergies all their lives.
Of course there are limits, and no sensible person would advocate complete disregard of hygiene. But all this disinfectant is both unnecessary and counter-productive. The old-fashioned commonsense rules about domestic cleanliness are not only adequate but optimum.
