I would love to participate, but simply do not yet have the equipment to make quality recordings and don't think it would be a good idea to mess up everyone else's efforts with a poor quality submission.
However, I would like to offer a suggestion based on something that I have been "playing around with" using Audacity recently:
What I have done, successfully, has been to take two "body" files, each recorded by different people and already containing subliminal tracks and music, and overlaid them in such a way that the secondary (subliminal) track of one of the files is barely audible and the music in the background is inaudible when the combined file is played at normal volume so that, instead of having an:
sounding final track, the end result is:
(with the D track slightly-2dB-louder than the C track)
(barely audible)
(inaudible)
The results were better than I expected in terms of the effectiveness of the file that was created.
I've done this twice, using different original files in both cases. In one instance, I added a third, binaural file, as a constant background throughout at a volume than the "A" track because the background music tracks ("C" and "F") on the two files allowed me to do that.
The content of the files that I used was different, but the messages were compatible. I would have preferred it if the files that I used had not contained a background music track, but I wasn't able to remove the music without interfering with the two vocal tracks and the effects used on those tracks. Had there been no music, I would have added another subliminal file with a third, compatible message--and based on the results that I got, I'm sure that it would work.
So, what I'm suggesting is that you could make a file that could be composed of three different tracks, each recorded by a different hypnotist, using different scripts each with its own, different message and having its own different effects (ie, one track recorded using the delay technique that EMG uses in his subliminal recordings; another one using a primary script recorded at a higher volume than a background reinforcement looped script; and the third an echo and sound-shifting effects)--as long as the message content of the three scripts are compatible. Depending on how you want to do it, you could bring in the second set of three new hypnotists (each with his/her own script) at the same time or in staggered times as the body of the file continues. As long as the subject/content of the script(s) remain compatible, you can make the file as long as you wish (I haven't done this yet, but am planning to make a test file in this manner when I get the chance to do so).
Once you have this part of this file complete, you can consider adding binaurals and/or a background sound (music or a neutral natural sound like rainfall or the sound of a brook, etc.). I'm not sure what would be the most effective way to do this yet (ie whether you lay these tracks on top of the combined file of the three hypnotists reading their scripts or if you insert them into those files before they are combined), but I'm sure that some of the more tech-saavy people here could advise you on that.
Based on the results that I have had with my experimenting in this regard, I believe that it is possible for this project that you have undertaken to produce a very interesting and effective end product. I have found that the file that I made with two subliminal files and the added binaural track creates such confusion when I listen to it that I go into trance (albeit a fairly light trance) even if I have not used an induction and am not totally focused on listening to it. With a good induction (I'm not sure if it would be a good idea to have three different hypnotists doing the induction unless you had one as the primary track and the other two reading the same script or a reinforcing script in the background), I don't even think a deepener would be necessary to make the body of the file very powerful for the listener/subject.
I wish I had a halfway decent microphone (I just have the one that came with my headphones)--if I did, I would love to take part in this project. I think this is going to be a lot of fun and am looking forward to hearing the end result!!!