It's dinner time so some people may be eating. Therefore, I won't give our gross experience which *would* have you washing it, but instead just trust me on this one. I'd certainly wash the lettuce if it was me!
Yikes! I dont usually buy the salad in a bag, but the few times I have, it never occurred to me to wash it. What do you wash it with, just water or the stuff they sell? I think Arm & Hammer makes something. I usually use just water on a head of lettuce, other vegetables and fruit.
I just wash it in water then spin it dry. But I do know some people use it right out of the bag. I wonder why they are allowed to say it is "ready to eat" if it is not? I did see a news show years ago about washing it first. I wonder if this lead to better cleaning and bagging?