It wasn't my intention to be sarcastic, english is my second language so maybe it was that, but anyway my main source is that its a tradicional and indigenous use of banana peel (thanks for pointing out its not skin. I never tried to search for the science behind it, I found this: http://www.scielo.br/scielo.php?pid=S0102-86502013000100006&...

You didn't come off as sarcastic. It sounded to me that you were matter of factly pointing out something that you use as a skin remedy, in an entirely unoffensive way. Don't worry about it, your English is fine.

Your English is fine...I also took it as sarcasm because it sounded so implausible.

There's actually a lot of research behind what you're talking about -- you'll find more looking for plantain or "Plantago Major L" and search NIH (restrict the search using site:nih.gov if you're using Google or DuckDuckGo).