If you use isopropanol, the version that's more pure works better. Standard rubbing alcohol is 70% I think, but you can buy 90%. The main thing is to NOT breathe the vapors, but this is usually not a problem because they smell weird anyway. The trick when cooking is to cover any pots or metal cups with a good lid. Otherwise some of the alcohol vapor can condense on cooler surfaces and drip down into your food or drink.