Holding your breath …
I wonder if the red herrings were references to Magician and a Kid. Perhaps this was done to throw you off the scent, a bit of smoke and mirrors perhaps.
6 minutes seems like a long time, but is it? Then 10 minutes is even longer and so would suggest “impossibility”. But what is Magic? It is sleight of hand, smoke and mirrors but could it also be real?
Is it possible this was some sort of Educational Stunt? It is probably not very well known, but breathing (not your everyday breathing that you do subconsciously) is a very important way to improve your health. Indeed, people have written books on the subject, and some people have even read them 
Given the target of 10 minutes is totally achievable [research shows that the current world record for holding breath underwater is 24 min 34.37 sec, this sounds as though this was done as a public awareness stunt by a couple of public spirited individuals, the Magician and his Assistant (all magicians have an assistant) The Kid.
The Kid was actually a disguised adult who had practiced breathing techniques and was easily able to hold his breath for much longer than 10 minutes, but in order to convince the audience this is something they can do, they pitched it at a more achievable level.
Obviously, there are trade secrets involved and which cannot be divulged, but one of the things this act was keen to promote was Breathing Through the Nose.
Breathing through the Nose
To keep it simple, I will reference a podcast and leave a link below so you can listen to it and say that there are benefits to breathing through your nose as below
“It’s a simple way to get healthier gums, a better memory, and improved lung function. How? Well, it may partly be due to a special molecule called nitric oxide. Michael Mosley speaks to Professor Jon Lundberg from the Karolinska Institute in Sweden who made the fascinating discovery that nitric oxide is produced in your nose and travels to your lungs where it has some surprising benefits, including boosting oxygen uptake and possibly helping you fight off infections.”
Of course, some of you will be familiar with this topic and also with the part Nitric Oxide plays in health.
Here is the link to the podcast by the [late] brilliant Dr. Michael Mosley
Perhaps this is jut one thing you might want to take up !!!
