We wash tangerines, oranges and watermelon or fruits that we cut out peel that may touch the inside. We do not wash bananas.
I do now as of 2021 only easy organic bananas. I noticed the fruit of bananas was tough inside and not what I was used to of 50 years ago I started buying organic bananas and the quality of much better.
It might be a scam but empirically it seems to be a good value.
I don't wash the bananas though.