I understand the idea of removing the basic dirt and grim that could still be left on the surface of the lettuce. But the idea that running the vegetable under the water has any help in sterilizing it has to be pseudoscience. Too many adults have this mentality that washing produce purchased from the grocery store drastically reduces your chance of food born illness. If your food is contaminated with harmful microscopic organisms in a food outbreak. I doubt washing it is going to change much.