For years I thought that the only way to get in lettuce was to wait for the entire plant to grow large and then uproot it. Then I discovered that you can remove a few lettuce leaves at a time for a sandwich or salad and not the entire plant.
When you go out and get a lettuce plant or a few leaves of lettuce you can use the hose to clean the plant or leaves where the plant is in the garden. For me I will break away a leaf then wash it with the garden nozzle on the garden hose so that when I take the lettuce leaves inside they will be clean.