Delayed response is a well documented phenomenon, and is one of the dangers of not removing undesirable suggestions given during trance. The lack of an immediate response to a post-hypnotic suggestion does not mean that it had no effect. André Weitzenhoffer (1957) reports in his book the case of a student who took the Stanford Scale test with no apparent effect but woke up the next morning with a partial paralysis. I have a published letter to the Editor of the American Journal of Clinical Hypnosis describing three cases of delayed effects (Ewin 1989). This has led me to an all encompassing wipeout alerting suggestion, saying “When I say three, you will open your eyes and come back fully alert, sound in mind, sound in body, and in control of your feelings. One (pause), rousing up slowly, two (pause), three.” An increase in tone and volume on “three” helps effect a change to full alertness. Richard Kluft (2007) has stressed the importance of fully terminating trance, and the dangers of neglecting it.
My premise is that if the patient is suggestible enough to accept one suggestion in trance, he/she is also suggestible enough to be sound in mind (not goofy), sound in body (no unwanted motor or sensory aberration), and in control of feelings (not an emotional disaster).