I don't think lettuce has a barrier to lose. I don't rinse cucumbers, squash, or melons and their skin is waxy like an apple.
Cutting out the stem/separating all the leaves and rinsing and soaking for 5 or 10 minutes extends the lettuce life in the fridge by a week or more than just leaving it in the bag it came in.
Same with strawberries, rinsing them when you get home (not soaking like lettuce) extends their fridge life.