That's a tough call. I'm fairly new to Liver Flushing with only 2 flushes. But I know it leaves me feeling washed out the next day. I'm assuming you want to be as energetic as possible for the job.
I know the epsoms will relax the ducts to get things moving. Others who've been doing this longer will no doubt have better advise for you. I just happened to see your urgent post and didn't want to leave you hanging out there.
There is something you can try that would be fairly harmless but could possibly bring some relief. I've been doing accupressure on myself for years. If you have a firm ball (like about the size of a golf ball), put it on the floor and step down on it with your right foot. The area you are trying to get at is about miday from front to back, but closer to the outer edge of the foot. Bear down on it and see if you can find a really sore spot.
If so, bear down and roll it around as much as you can stand. What you're doing is relaxing the muscles and bringing energy flow to the gallbladder area.
It's worth a try. I've stopped headaches, sore throats, and lots of other ailments using this.
Even if it brings some relief, it is, of course, only a temporary solution until you can do a flush.