Am I the only one to have edited out school toilets? With some effort I can remember smelly unhygienic generally horrible facilities. At the same time we didn't all (50%+?) have asthma, allergies and skin problems. If a mother is to transfer any sort of immunity to anything in her milk she has to have met bugs and bred bugs - those horrible toilets were a really good place for doing that.
Kind'a contraversial to suggest actually taking out the soap on the grounds that what doesn't kill them makes them stronger. I dunno.
As an aside - next time (if) you are in hospital watch the guy/guyess that brings the tea round - do they ever wash their hands? They're under the radar yet they can spread an infection to every patient in every ward within 8 hours. Just saying.