Thank you Peter, Mike, and Zavk. I have often wondered about whether the experience of bhanga was power of suggestion or something unique to the technique. My experience was that it happened for me first, and then Goenkaji stated in the audio recording after
it happened something like "By now you might be experiencing this sensation all over your body, we call it bhanga." After the retreat I checked with others, and they all said the same thing: they had the experience before
Goenkaji discussed the experience in the recording, so it did not seem likely to be power of suggestion. But in the next session with the teacher, the teacher asked each individual if they had experienced it, and almost all stated yes. I have since had many conversations with people who are loyal to that technique, some have been on many retreats, and everyone I have spoken with stated that bhanga is what has them coming back for more. But when I speak with other Buddhists about that experience, they stare at me like I am a crazy person (which of course I am...).