Yes- you could do a fast beforehand if you can tolerate it ( I don't do well skipping meals myself :-). In fact, Julia Chang ( chinese herbalist who's site is http://www.sensiblehealth.com ) advises doing an apple fast before a flush. It's on her site ( I can't recall how many days it lasts ). Yes- For best results it's recommended to take some sort of stone disolving agents for a week prior. But if you do the apple juice fast, that would of course be all that was needed. :-)