Former classroom teacher. Used to have my students do a science fair. One of my students decided to swab his hands and his family’s hands after using hand sanitizer and after washing their hands. Then he placed what he swabbed into Petri dishes. (Dad was an M.D.) It was THEN that I ALWAYS taught my students to wash their hands because that bacteria from sanitizer was nasty looking! (This Dr. Dad was also the first person I personally knew to fist bump rather than shake hands).