I think physicians learn in their studies that washing one's hands does not help all that much. They do actual experiments testing how long you would have to rinse your hands to get a significant amount of bacteria off it - it is a very long time.

Recently I read a study (or talked with a doctor who told me about it, can't remember) saying that it is actually more efficient to use disinfectants occasionally (ie on demand) instead of washing one's hands all the time. People tend to be wary of disinfectants because they tend to sting on the skin, but apparently the stinging is only a sign that the skin is already damaged. Apparently the disinfectants also contain stuff that is good for the skin, so using them is not as bad as it seems.