Stephen, what do you think of making recordings (cassettes, CDs, MP3s, whatever) of Ericksonian style hypnosis sessions? Seems like a great deal of the power of the approach comes from the utilization of a unique and unrepeatable situation.
At the most basic level, when they listen to it, the words are not going to be paced with their breathing anymore. At a more sophisticated level, bits of confusion& attempts to elicit amnesia certainly don't have the same effect when heard over and over. Metaphors would start to be analyzed by the conscious mind. Etc etc you get the point.