NEW YORK - Can you really cure the common cold just by swishing salt water through your nose? Yogis have been swearing by it for ages. Now, even Americans who've never said "om" are saying "ah" after trying the ancient Indian art of nose washing. To get at the source of their stuffiness, nose washers use a tool that looks like a tiny Aladdin's lamp, called a neti pot. They fill the pot with warm salt water, then ever-so-gently insert the tip of the spout into one nostril. Then they tip back the pot and let the waters flow. As...