Andreas Moritz recommends to have a bowel cleansing before doing the liver flush. He recommends Epsom Salt during some days in the morning ( no to take for a long period of time).
Enemas are good. The recipe for coffee enema is in the description of this forum. It is easy do to, you can use any enema bags.
The trick is to have one water enema first, the two coffee enemas. The first one cleans the bowel and the second two ones are retention enema. It means you have to keep the coffee inside for 15 minutes each. That is why you use a little amount of coffee.
Additionally you can have during some days organic apple juice for softening the stones. It contains malic acid and pectin and it is really good for the liver. You can begin with it to night and tomorrow morning. You can take a glass every two hours. Warm juice no cold because it chills the liver. Eat something like oat meal in the morning.
After that you can have your liver flush. It will really help you and it is safe.