I think Nlp has been discredited, both in claims to success and in the jargon they use. However, the similarities between self-hypnosis and meditation are interesting. As a student, many years ago now, I used a self-hypnosis tape that had a blank space for inserting whatever you wanted to change- smoking, stress, whatever- and used it many times. When I later came to meditation I found the relaxation part of the tape useful for getting me 'into' the meditation.
Later on when I joined a Buddhist group it helped me relax during the body scan parts of a meditation, and whenever I needed to bring my thoughts back to, say, counting breaths. It allowed a better relationship between body and mind.
As to the other aspect, that of using suggestions whilst in a relaxed state is a bit more dubious, and where the two part company. When I did that, instead of using the gap in the tape to impose a message on my subconscious I grew to use the quiet time remain in the relaxed state, before the tape brought me 'round' so to speak. In my experience during meditation, even in a large group, there was no autosuggestion taking place, no message from the person taking the meditation. If there was chanting it was in Pali or Sanskrit but never in English.
The Buddhist path is much more than making suggestions to people in a receptive state, but maybe there are elements that are similar. Perhaps visualisation meditation is closest, where you visualise a personified aspect of the path such as Avalokiteshvara who is big on compassion. As you say, interesting to think about.
