there was just an article this a.m. in the news paper about vinegar:
if there are hard water stains on your glasswear, boil vinegar, pour over glasswear, and scrub with non-scratching pad. it's supposed to work.
i also used it to clean out and freshen my cats boxes. they weren't crazy about it, but they got over it.
isn't vinegar the product of wine or wine grapes that have been sitting around too long?