The standard Clark flush coopted by Moritz is low fat the day of the flush.
Save your bile also does not make sense, as someone recently pointed to a study that Epsom Salt is a bile stimulant. So why would you take a bile stimulant before drinking oil.
Dr. Kelly on the other hand suggested high fat (ice cream, peanut butter, whipped cream, etc) right before the flush to prime the pump. I tried all the different flush methods.
There is no exact correct way to do them. Whatever you find that gets the most junk out over time is the correct way for you.
Abstaining from animal products can work for some people and some not.
I found that the most important factors before a flush were: hydration, keeping the intestines moving and making sure your gut is as relaxed as possible right before you ingest oil. I never found abstaining from animal protein to be important, but to each his own. Probably blood type A's and others who do better as vegans would benefit most from this.
In theory malic acid aka apple juice should work but it never worked for me. Also I found that sludge is actually more difficult to pass than actual stones.