I'm guilty of one of the seven deadly brewing sins. I did not clean my better bottle after bottling my brew. It was a late night bottling session and I ended up putting it in my storage room before cleaning. I was looking for Christmas stuff and come across it and it looks rough. The bottom and top look pretty moldy. I have some oxy clean in it now. As far as I know the bottle wasnt scratched so I dont know if they have a place to hide, but I'd hate to throw a brew in there and it be ruined by my neglect of the fermenter.