I asked the Centers for Disease Control about soap and hand sanitizer. Below are the responses. But the “quick take by Bloomberg” link has more specifics from Professor Palli Thordarson.
Sharyl Attkisson: How long should someone wash hands?
CDC: CDC recommends cleaning hands in a specific way to avoid getting sick and spreading germs to others. The guidance for effective handwashing and use of hand sanitizer was developed based on data from a number of studies. Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing. If soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol. Cover all surfaces of your hands and rub them together until they feel dry.
Sharyl Attkisson: Does hand sanitizer work to kill coronavirus?
CDC: CDC recommends washing hands with soap and water whenever possible because handwashing reduces the amounts of all types of germs and chemicals on hands. If soap and water are not available, and hands are not visibly dirty, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others. However, if hands are visibly dirty, always wash hands with soap and water.