Both kinds of alcohol will pull water out of the air, so if it's above a certain percentage alcohol, it won't be for long. The kind you get at the gas station as fuel anti-freeze is supposed to be very dry- I don't know the percentage, but you're not supposed to use it if it's been opened, because then you'll just be adding water to the tank, instead of taking it out like it's supposed to. The stuff in the yellow bottle is ethyl or methyl, and can eat the rubber seals in the systems of some cars- the red bottle is isopropyl and is supposed to be safer.