I have fasted. I find it to be very cleansing. Drinking just pure, clean water gives your body time to eliminate waste and toxins without having to deal with the stress of the digestive process. I fast for 3-5 days at a time. I drink only water or herbal tea during this time; get extra rest; and get gentle exercise (walking, swimming, etc), I also scrub gently and extremely thoroughly while bathing because during a fast a lot of toxins are eliminated through the skin.
Try it - you'll like it.