they did clinical research.
Arcadi Petrov has a clinic in Moscow, people are welcome to go there -with an interpreter- and check out his files. We contacted him when I took their course and he said he was willing to meet with us, so nothing hidden or weird.
Having a clinic collecting evidence was fairly easy, you get someone in with a problem, have X rays and MR to prove them and take the same tests after the healing took place.
Problem with clinical evidence of people who work against the system is that it won't be taken into account (see case of dr. Hammer for cancer with above 90% success rate proved by MRI before and after - worked only to have his license taken from him when he started to call the doctors applying chemo 'criminals' - or the case of Dr. Di Bella in Italy, ridiculed for a cancer treatment protocol that used bicarbonate of soda - way too cheap- so they took his license and only reabilitated him after he died, taking over the cheap protocol that now costs a prime).
Arcadi Petrov is a dotor, his daughter is a doctor, they didn't make the same mistake to go public too soon, they collected a lot of evidence on their protocol, ask me how it works or why? No clue, so I can't give you more info on this specifically apart from the fact that it is based on numbers and visualizations and statements that must always be preceded by a 'master code' for the 'upliftment of all of humanity' - has Grabovoi designed these codes into the Matrix and allowed access only to those that ask for the good of all first and then for themselves- again, no clue, these questions I have asked myself with no answer.
For what concerns organs regrowth, this is actually a well known subject if you had delved into the possibilities of the new medicine, the US army has been doing this research and now we could say protocol for quite a long time -research that- and some creatures in existence already do it, like lizards they regrow their tails, so it's just an information 'for growth' that the body needs, you may have heard about phantom pains. those are the pains left when someone loses a limb - ample research on this- this would be counter-intuitive, how can you have pain in a missing arm?
The answer is that the 'arm blueprint' is still there, it's just not visible to the naked eye, it has to be 'refilled with substance' so to speak.
Bernard once spoke about the ability of the body to regrow a 3rd set of teeth,many things are possible, they don't become impossible just because we don't know about them or don't believe them, so if you want to know more about this, you can research in the lines of what I told you or take a plane to Moscow, Arcadi Petrov will be happy to show you, but can you see what you don't believe - anyway? Wondering