Just like with washing with soap and water, there is a proper way to use hand sanitizer. For alcohol-based sanitizers to work, they must be rubbed all over the hands until completely dry (about 20 to 30 seconds). Don’t rinse or wipe off the product, or it won’t work as well.
According to the World Health Organization (WHO), alcohol quickly kills germs when applied in the correct amount. However, “if hands feel dry after being rubbed together for less than 10–15 seconds, it is likely that an insufficient volume of product was applied.”