well all my bags have never been treated.
BUT on my batignolles i used to put on a lot, i mean a ton of lotion on my hands and it would get all over the bags and it was my first lv and i didnt know anything about it and i took it out into the rain, i mean pouring rain and now the patina is a medium colored honey and its only been 6 months. stupid me. haha but its still gorgeous.