My friend Dr. Carmichael who runs the epidemiology lab at Columbia Presbyterian Hospital in NY got on his sister Isabel's case when she was inclined to stop her child Felicity from eating something from the floor. He suggested that if we are all raised as hothouse plants that our immune systems won't develop. Not to offer a rebuttal as I'm sure Dr. Carmichael practices good hygeine in his medical practice and would generally agree with everything you said. I don't think if "Fifi" was eating off the floor of a bus station rest room that he would say what he said. The fact that you're not watching a child every minute provides time for the child to have plenty of times to test his or her immune system and though I'm sure Dr. Carmichael's point should be considered - it's a reason to get your children into good habits. If a virus is loose, it may be too late simply washing your hands after someone has sneezed in your vicinity where air circulation isn't good. Try flying a plane these days. One sick person can taint the whole air supply. What are the odds? Good I'd say. As good as the bouncy market continuing to bounce. Wash your hands after bouncing balls and do have a ball. It's almost Chinese New Year - aw rat aw rat! Think of clean white rats with nice pink noses. No plague here!
Dr. Carmichael in his junior year at Andover won the 2nd place in the National Merit Scholarship tests in the US in 1966. The following year he entered Harvard as a sophomore and got his degree from Albert Einstein probably two years before Howard Dean who is his same age.
I trust Dave Carmichael's opinion. I do wash my hands. In Yoga, cleansing has a whole other meaning than washing hands although good hygeine is required if stuffing gauze that has been soaked in saline down your throat without choking on it (which takes training) isn't your idea of how to clean the esophagus. I wouldn't try that at home.
Most yogic cleansing has to do with the breath and how it moves the prana though the chakras removing impurities of spirit. There's another subject to come back to. First - wash your hands. And wash your feet too - already! Don't forget behind your ears!