For banana skins, you can turn them into a vegan bacon. Many recipes online that are all pretty much the same result. I like them too.
I should try again sometime with a regular cucumber pickle recipe, just replacing cucumbers with watermelon rinds, but I don't think my family wants to humor me again.
We throw away a butt-ton of watermelon rind in the summer. I never thought to see if they could be used for something.