After the flush, when we examine what is in the toilet, it's not all one thing, or a least it wasn't for me. There have always been quite a variety of surprises in there.
Some things, such as soft small round oily balls, could very well have been caused, as you say, by the ingredients combining with something already in the body.
Other things I've shat into the toilet definitely were not made in the space of 1/2 an hour in my intestines. NO WAY.
Flushes for me (I have not done one in quite a few months) usually followed this trajectory:
I felt great, symptoms reduced or gone, for a few or as long as 10 days or so. Then, slowly, my symptoms returned. This is standard-issue.
I guess this is why they say you just have to keep on going. Maybe flushing will never make us 100% healthy, probably not. But we are tired of medical doctors and their B.S. and that is why we keep trying.