However, what we know about psychs is that there is a huge release of BDNF (brain derived neurotrophic factor) and a shutdown of the DMN.
The BDNF enables a ton of new neural connections to be built. It's like you have about 6-8 hours of a period where your brain plasticity goes back to that of an infant, just absorbing everything. So in this accelerated learning state, it's possible to work through one's emotions.
So it makes sense to prepare for several weeks to receive therapy and to outline goals and memories to revisit to process them during this heightened period. Then when the drug wears off, you're still left with the new neural connectivity and perspectives and the other benefits that were derived from the session.
Rather than hitting the vacuum tube, this is more like re-running the radio scanner in your car to find radio stations when you've moved over to a new city and the old radio stations are now out of range while one isn't tuned to the current set of radio stations.