You get it in a 10 oz. bottle. Epsom Salts aren't necessary for a successful flush. Many people do flushes all the time without them, including myself. I've done 15 flushes, no epsoms since flush #5.
You should be able to follow the classic coke flush with no problems. Evidently, the phosphoric acid in Coke helps break down and soften the stones, at least that's what I've heard. If you feel better taking in apple juice before the flush, do what you are comfortable with.