The magnesium in the epsom salts is a smooth muscle relaxer just like the orthohosphoric acid in the Ultraphos. That's one reason why it is used in the Clark liver flush. Those who have bad livers and dirty colons NEED some of the ES, but the recommendation is to put a pinch of it in some juice or water to bowel tolerance every day.
To me, there's no reason why, if you sip on the apple cider with the Ultraphos in it ALL DAY for 3 daysin a row, that you wont get stones out of your liver IF your liver has stones in it. To me, there ws no need for the TBSP of ES in water 2 hours before a liver flush in addition to the Ultraphos drink. There is Jsmom and maybe others who have done the ES drink pre a liver flush. Look up their posts.
Also, my colon was in bad shape, and I couldn't do the ES in that amount either pre or post a liver flush. It was too much ES at once. If you're very constipated and having a problem with bowel movements, maybe it will help you after doing the flush or both before and after. It IS a laxative and isn't recommended for people who have bad colons and livers to do as the only kind of liver flush. We recommend the Coke flush, if you have to do them close together. They won't dehydrate you.
IMO, you don't need the ES for the purpose of making the bile duct flaccid enough to help stones to pass thru that duct if you do the Uphos drink correctly. But that's just MY opinion.