Hey folks, I have recently acquired a nice glass 5 gallon carboy from a relative's estate sale that they just gave to me. The only issue is that it has clearing been sitting in a basement for quite some time and appears to have a small bit of rust on the inside of the carboy from who knows what. I have tried basic soap and water, borax, peroxide, the ol coke trick, and sand in water as an abrasive. Anyone have any tips on getting this thing clean? I'd lime to avoid harsh chemicals as this will soon hold wine. Oh and its got a narrow top so getting a brush inside is pretty nigh hopeless.