Thank you so much for answering my question. So good to know. I actually just hopped on here to say that I made it through the cleanse! Barely, though. A migraine started threatening, but never went into full swing. And the cleanse really does work like they say it does! I'll definitely be continuing with these after the holidays.
I followed Moritz' protocol. I've heard it's similar to Clark's, and I'll try to read that book, too, as it sounds, from what you've said, more specific on certain aspects.
That makes sense about fat being the thing to really avoid. But I'll just list what I did differently this time, in case it helps someone else.
On cleanse day morning, I drank malic acid in water, instead of apple juice, in order to avoid blood Sugar
swings and crashes. (Didn't switch earlier in prep bc I was waiting for malic acid I oredered to arrive.) But in the days leading up, I tried to make sure I was getting moderate amounts of healthy fats, whereas before I avoided it too much, out of fear of another gallbladder attack. On cleanse day for breakfast, in addition to oatmeal and fruit, I had a store-bought smoothie made of fruits, juices, and "almond protein flour". Which seems to have less fat than actual almonds--0.5 g per 100 ml smoothie, to be precise. For lunch, in addition to vegetables and rice, I added some brussels sprouts and black beans. One or both of those also has very small amounts of fat, if I recall correctly--but it didn't ruin my experience.
My best guess as to why I've been gettng migraines from this, is because I'm undernourished/deficient in some nutrients. Mostly, I believe, due to drastically decreasing my food intake for 3+ weeks following my gallbladder attack (what got me turned on to the cleanse to start with), because I had no appetite. So the restricted diet taxes my system a lot.
It's wonderful to get this gunk out of my digestive system, and I look forward to doing this even better next time.