No, haven't tried it, but it attracts me. I noticed how significant the tranquility of the pulse and breath is during any entheogenic experience. Controlling it in the deepest relaxtion, makes an experience peak in vividness and does a lot of good to the memory. I feel nowadays I can dive even deeper than ever before.
Seems to me that this aspect is even much more important with Iboga, health wise and to get the proper reward out of it.