The hygiene literature runs deep. I enjoyed the observational studies showing that men spend e.g. 3.5 seconds washing hands, women a little more (though both are probably averages skewed by abstainers).

It doesn't seem like we know much. The research is disconnected from reality. Soap and water, used as directed, are effective at mechanically removing microbes, but you're going to touch a knob or phone or keyboard in another minute anyway. Dry hands transfer microbes less so it helps to reduce moisture residue.

Disposable towels have a "friction effect" that removes microbes after a 3.5-second wash, but it is hard to standardize, so study participants just press their hands on a towel for ten seconds. Dyson warns that people leave moist paper towels strewn about the WC, or try to flush them and cause overflows. But no one ever picks up a paper towel from the floor to wipe their nose. The air dryers (tested when new, and not contaminated by use) tend to blow particles all over the place.

I appreciate having a single-use barrier with which to grab the doorknob.

Everyone measures bacteria (using titres of "glove juice") but do bacteria make people sick? Sure they do, and pianos can kill, but I worry more about viral infections. Probably that is harder to measure.

Manila: another Waterhouse for another time.