I have used CLR for cleaning bottles with rust stains. I find that it works rather well but sometimes you have to clean them with it a few times to clean off the rust stain. If the rust stain is rather bad you might soak the bottle in a diluted solution of the CLR and some water. If you are cleaning ACL bottles with painted labels you might not want to scrub the label too hard with the CLR as it might scratch or peel off. I hope that this info. helps!