I’d guess that washing your hands has some diminishing marginal returns, so if washing your hands for 30 seconds 15 times a day is approximately as good as not washing your hands at all, you can probably do better than both by being somewhere in the middle (e.g. washing your hands for 20 seconds at the 10 points during the day when they’re most dirty).
My personal guess would be that if you want to minimise the time cost of hand washing your best bet would be to really drill in (a) always washing your hands before touching food, and (b) not touching your face. If you can be very confident in those two things you can probably let up on the general hand hygiene slightly. I was going to say that this applies if you don’t care that much about externalities, but to be honest if you always wash your hands before touching communal food you’d already be doing much better than most people.
You mean this one? Yeah, that does suggest that there are increasing marginal returns to time spent per hand-washing session, at the typical level of effort.
My personal guess would be that if you want to minimise the time cost of hand washing your best bet would be to really drill in (a) always washing your hands before touching food, and (b) not touching your face. If you can be very confident in those two things you can probably let up on the general hand hygiene slightly. I was going to say that this applies if you don’t care that much about externalities, but to be honest if you always wash your hands before touching communal food you’d already be doing much better than most people.
(ETA: Also see David’s other comment below)
You mean this one? Yeah, that does suggest that there are increasing marginal returns to time spent per hand-washing session, at the typical level of effort.