Your Best Friend In The Beauty Department. In a constant search for the fountain of youth, Americans are pushing the skin care market to record sales levels. According to trade magazine Cosmetics International, sales of moisturizers, cleansers, hand care products and body lotions are predicted to reach $7 billion by 2010, thanks to double-digit growth from anti-aging products. But if you’re among the big spenders, you may not realize that one of the best beauty secrets could be hiding in a 40-pound bag in a corner of your basement. The secret is salt. That’s right, salt. It’s contained in home …