Personally, I prefer a mono-fruit juice as the ideal fasting juice.
I've done The Master Cleanse too. The part I disliked was the Epsom Salt flushes. Now I mostly do orange juice fasts along with herbs.
Also, if things are coming up and out, your liver and colon may need cleansing. Your digestive system needs to be moving things down and out before starting a fast. So preparation is key.