Some people have substituted Epsom Salts and there are some who have used no Epsom Salts at all. But, for me, I truly believe Epsom Salts plays an extremely important part in the liver flush. It's because of the epsom salts that you feel no pain when passing the stones.
When I first began flushing, I couldn't stand the taste of epsom salts, but could tolerate the olive oil. By the next morning, I would really be gagging at the thought of drinking epsom salts. (I later discovered that mixing the juice of a lemon with the epsom salts helped the taste.) But, I continued my flushing because of the results I saw. Plus, I would think how much money I was saving by NOT having surgery. The Liver Flush took only a few hours out of my day every couple of weeks, so what wasn't to love about the Liver Flush besides the taste? In my opinion, that's a very small sacrifice to make with all the positive results you see inside and outside your body!
After a few flushes, I began to tolerate the taste of epsom salts and loathed the olive oil. To this day, the smell of olive oil makes me gag!
I have since found a little epsom salts every day keeps my heart in rhythm, so I mix a little in my SuperFood everyday.
For more information, go to the top of the Liver Flush Forum and click on all the great information listed. You will spend hours learning about the liver flush.
P.S. Oh, and I did flush until I was stone free.