In a heartbeat that strangeness is forgotten. I feel a surge of anger that is almost frightening in its intensity. I am almost overcome with the desire to get up and punch the bare white wall in front of me in the hope of smashing the plaster.

I open my eyes and tell Paul McKenna that we have to stop for a moment, sit back and attempt to catch my breath. "Sorry about that. These sessions aren't always easy. But we need to get to a place where these emotions you're feeling are in equilibrium," he says.

So we start again. 

This has been an unusual Tuesday morning for someone accustomed to writing about the financial world. But there is a reason I've been picked for this assignment. McKenna, who has undergone a remarkable metamorphosis from Top Shop DJ to TV hypnotist, to self help guru and multi-millionaire businessman, wants to demonstrate his "Havening Technique" on someone whom it is intended to benefit.

He is "very confident" that person (me) will come away from it in a better place than when they entered so he had asked for a trauma victim when his people contacted The Independent for this article.

I fit the bill rather well: just over two years ago I came about as close to losing my life as it is possible to come when a tanker ran over me while I was cycling in London. The psychological trauma was profound – and not just from the accident itself. I endured a three-month stay in hospital, the first three weeks of which were spent in a coma. The drugs they pumped into me also triggered a succession of disturbing, and frighteningly vivid hallucinations when I came out of it.

Five months of therapy, arranged by my lawyer after fighting a losing battle with the NHS, helped to repair some of the fractures in my psyche, but recently the demons have been jabbing, especially at night. So, while I'm generally suspicious of the self-help industry, and its gurus, I was more than willing to give McKenna a shot.

In person, he doesn't come across as starry, or at least not the bad kind of starry. He spies us struggling up the road towards his office and comes out to meet us. He doesn't look particularly imposing. He wears glasses, and a comfortable-looking suit, no tie. His office-cum-London pad is squirreled away on a Kensington mews street. It's the sort of place that would give hot flushes to those who indulge in property porn. But inside it seems pleasantly disorganised.

I had wondered if there would be any evidence of his time as a TV hypnotist, given the aura of respectability he now cultivates. He, and Havening's creator, the American Dr Ron Ruden, are looking for the credibility academic verification of Havening would bring by submitting their research for peer review, and McKenna hints that a big announcement is in the works.

But he doesn't disavow his past. There is a framed poster on the wall featuring a youthful, and slightly sinister looking McKenna bearing the legend "The Hypnotic World of Paul McKenna".

McKenna became an advocate of Havening after the technique was demonstrated on him after a particularly nasty break-up, of which he has spoken previously.

You think of a really nasty memory, establishing it clearly in your mind, and rate its intensity. You close your eyes and tap on your collar bone. You then open your eyes, clear your mind, and think of something pleasant. You then follow the therapist's finger moving rapidly this way and that.

After this you relax, and he rubs the top of your arms, while you imagine, say, tapping a keyboard, counting up from one to 20. You hum a few bars of a tune (say "Happy Birthday", or the national anthem), close your eyes for more arm rubbing, open them and rate the trauma's impact afterwards. After that it's lather, rinse, repeat.

The therapist, so it is said, doesn't need to know the nature of the memory. Just the technique of desensitising it.

McKenna says of the effect on him: "In a matter of minutes something I was sad about, angry, even furious about... The emotion was gone. A lot of people say this is a distraction and it'll come back. Yes, sometimes you have to reinforce it, but with most people you don't. I didn't need to.

"I had a big bright picture of this girl and a whole load of anger. But not only did this image of her move, it stayed there, even when I tried to pull it back. It is like I had been rewired."

That rewiring healed his broken heart, he says. It's quite a claim, but it was quite a break-up. McKenna's ex brought her new beau back to his pad while the two were together. "They even helped themselves to my Chateau Latour," he says, a reference to the expensive claret of which he's fond.

McKenna says he feels not the slightest hint of bitterness about the bust-up now: "And I don't expect to if I live to 100.

"Ron said to me he'd explain all the science, so I sat there for six hours and went through all the process of learning about it.

"Ronnie has a photographic memory and a brain the size of a planet. I really had to concentrate but suddenly, three or four hours in, I said, 'I get it. I see how this works. It de-links the thought from the feeling.'

"The point of, say, fear, is to keep us safe. To stop me from doing something stupid, like stepping off the kerb without looking. Anger is more about standards being violated.

"Uncomfortable emotions are a signalling to us. It is when they are over-signalling, that is when it is uncomfortable and spoils our quality of life. People can't enjoy things as much as they should. We want to reduce that over-signalling."

Havening at least claims to change the chemistry of the brain. So did it work on me?

Up to a point. Some of the more traumatic memories, which I thought had been addressed by therapy but which have been leaking back in, are again in abeyance.

A second part of the process involves you conjuring a strong emotion related to the trauma: fear, anger, frustration. You chant the word, with more of the arm rubbing. That's how I came (briefly) to want to ruin his plastering. I actually didn't realise that deep down I was quite so furious about what had happened to me.

The process is then broadly similar to what I described above. After intoning the negative emotion you think of something pleasant. I thought of being on a friend's stag do and, unbidden, one particularly amusing memory intruded. It's nothing too dreadful but I couldn't resist a guffaw and that did it. Anger gone.

However, the laughter wasn't actually part of the technique as advertised. Perhaps they should do some research there?

After the event, having felt moderately awful on the way in, I was much cheerier. The next day I was exhausted, horribly so, although that may have been down to the obstacle course involved in getting there (following the accident, my mobility is seriously constrained).

However, the next day I felt remarkably chipper. Much more so than recently.

That said, I'm not sure Havening is quite as miraculous as McKenna says it is. Psychological bruises from the accident remain with me and they're still sore. When he tried it out as a way of soothing the physical, neuropathic pain which is a constant companion, the effect was minimal.

He did say he'd like to have a second go at this, but since then his PR people have been fussing about getting medical records and doing it in public, and this has made me a little wary.

All the same, I'm sleeping better, I'm a shade more relaxed and, interestingly, I feel more confident driving.

So while I'd say the jury is out, and I'm sceptical of the 90 per cent success rate claimed given that it was only partially successful with me, I'm not quite ready to stand with McKenna's critics.