To keep your glasses from developing a hazy film, don't wash them in the dishwasher. Instead, wash them by hand with a mild soap, rinse thoroughly, and dry immediately. If you are trying to clean a cloudy film that already exists, note that hard water is probably the culprit. To remove the buildup caused by calcium and magnesium ions in hard water, start by swabbing the glass with acetone (nail polish remover), and then scrub gently with a mild detergent. Soaking the glasses in plain white distilled vinegar is another effective home remedy. But take action right away -- the longer you wait, the harder it is to wash away unsightly film.
Cleaning Cloudy Glasses
Martha Stewart Living, November 1997