another thing to have a look at, is how BKI gets people who have attended The School before to reattend. BK calls them "Staff", but they are not paid, they pay to work there, and to "help" people.
So perhaps some of these "Staff" also share rooms with newbies, and this creates a deeper social influence network.
On top of that, all the meals together, and the long days, etc.
So many of the seminar techniques, are not unique to Byron Katie, and are part of the LGAT seminar environment of social influence, similar to Landmark, PSI, or other multi-day long hour LGAT seminars.
Then inside that structure, you have the particular methods and content of Byron Katie.
But there is the entire layer that most people don't think about, or are not even aware of, the meta-level of these type of multi-day seminars, called LGAT's, "Large Group Awareness Training".
People can search google for
LGAT, or "Large Group Awareness Training".