If you have biliary sludge confirmed by ultrasound, you may need more than the occasional liver flush. From folks have reported in the past, 9 flushes would appear the minimum. As you go through the cleansing programme, you will see the stones change in shape and consistency.
The flush potion is very powerful, even if you take half the recommended. The Epsom Salt solution needs to of sufficient strength to contract the gallbladder as well as being a laxative. I would recommend having a high strength dose pre-potion and a lesser dose afterwards.
In respect of your migraines, have you considered that it may be down to caffeine withdrawal?