To clarify the line about water (I struggled to multi-task😅): a mixture of water & alcohol is better than 100% alcohol for many reasons - the water keeps hands from drying out too much, helps with penetration, and even slows down evaporation of the alcohol so it has time to work
But it’s the mixture of alcohol in your hand sanitizer that helps to dissolve away the molecules that make up the cell membrane of bacteria or outer coat of a virus.
Rupturing the viral coat or bacterial cell membrane alone would kill em because it means their contents spill out, but the alcohol also denatures (or kills) the proteins inside these pathogens that they need to function.
