I seem to have put my head into a hornets nest ,something I was actually trying to avoid with the "exercise". There is no secret here it is a very common and very basic Yoga exercise , Anuloma Viloma , I am sure one can find a description of it on the internet.But that is not the point !It is my belief ,having studied it in India with an exceptional Master, that it is not something easily self taught.
It is basically just going for the slowest possible inhalations and exhalations.No reputable Master will teach it to a student until he can demonstrate sitting in 1 of the classic positions for at least half an hour ,Padmasana ,Vajrasana , Virasana Sidasana
etc.The knees must be on the floor and the spine erect.
The student is constantly monitored for the quality of breath , this is paramount.If the inhalation is jerky after a long exhale the student is instructed that he is slowing down beyond his capacity.
His sweat is constantly monitored ,great heat is produced in this exercise.
And his bodily position.
MT and I achieved a rate of 60 breaths an hour after 2 months daily practice.A student is required to persist with this for5 months,before trying to master digital pranayama.
About 6 years ago I sent Sam Still ,who at the time had a 5 min breath hold to this Master ,he was there 2 months and came back and immediately broke a world static
record.
Diet of course plays a big part.
WE teach this in our advanced coaching and describe it more fully in our lectures ,I have never attempted to teach it over the internet.
It vastly improves the extraction of o2 ,its transportation and utilization, it builds a big resistance to co2 and done daily with 2 static practices per week has astonishing results. Good Luck.