When most people go on a juice fast, they get a juicer and actually juice their own fruits and vegetables to drink throughout the day. I am on a "poor girl version" of a juice fast because I chose to use V8 juice bought from the store. Most juice fasters would say that its not good to do that and I wont get the same results, but its my choice and I dont have access to a juicer anyway.
I assume by salt solution you mean the saltwater flush. It works like a laxative or enema. Its a salt water solution made by mixing 2 teaspoons of Sea Salt into 32 ounces of warm water and drinking it rather quickly. The flushing effect starts happening about an hour later and it will clean out anything that may be in your large intestines and colon if you are feeling a little backed up. I did one yesterday.