I once read that spending extra money for organic
bananas (as well as any other thick-skinned produce) is just a waste of money, which I know is not what you asked, but there is my two cents ;o)
As far as washing them goes, I just peel them. Why would you need to wash something you're not going to eat, unless you are cutting through it with the peel on, as in a cantelope? Not arguing, just curious.