We’re a nation – a globe, in fact - obsessed with our hair. Analysts at Goldman Sachs estimate the global hair products industry to be worth $38bn (22.6bn) – and growing at a rate of up to seven per cent a year。

There seems to be no limit on what we’ll spend to avoid a bad hair day. But for devotees of an underground beauty movement, the secret lies in ditching the shampoo, in fact all the hair products, for good。

The ‘no-poo’ method, which involves using natural substitutes or just water in place of shampoo and conditioner, has credibility within several circles。

Beauty insiders, including writers for women’s magazines and professional hairdressers, rave about how hair becomes thicker, fuller and more lustrous。

And thrifty environmentalists rejoice at the lack of chemicals in and on their bodies - not to mention the impact on their budgets。

Now one devotee is hoping to take it mainstream. Lucy Aitken Read, whose book Happy Hair: The definitive guide to giving up shampoo was released last week, hasn’t used shampoo in two years and her glowing auburn hair is visibly in perfect condition (see the photos if you don’t believe me)。

For her, the motivation came after reading a study that claimed women put 515 chemicals on their bodies daily. “I initially thought ‘Ha! They didn’t research me!’,” Aitken Read says. “Then I looked at the back of my shampoo bottle and realised there were loads of ingredients I didn’t recognise in the slightest。

She does admit she was worried about the grease factor. “My hair used to get greasy the day after I washed it and I was addicted to dry shampoo. Hand on heart, I wasn’t sure how long I would last。”

Paradoxically it’s greasy hair that could benefit the most from giving up shampoo. The theory behind the ‘no-poo’ method is that shampoo strips the hair of its natural oils, which prompts the scalp to generate more oils to replace them. This results in oil overload – greasy hair – which we then attempt to ‘fix’ with more shampoo. It’s a vicious circle and quite a brilliant coup for the shampoo industry, because the more shampoo you use, the more you need to use and the more frequently you need to use it。

Left to its own devices or washed with natural substitutes, the scalp eventually theoretically returns to its natural balance, producing enough oil to keep hair soft and smooth without the associated grease-slick. The oils produced by the scalp – notably sebum – keep the shaft of the hair clean, smooth and protected, performing the role of ‘shampoo and conditioner’ far more effectively than the manufactured alternatives. The upshot should be healthier hair that is stronger, thicker and fuller as it is less damaged than shampooed hair。

Most ‘no-pooers’ use alternatives to shampoo and Aitken Read’s book contains 30 different shampoo, conditioner and styling alternatives. Put together, they read like a cake recipe – bicarbonate of soda, flour, egg, honey, lemon juice. But after a period of time most find just plain old water does the job fine. “I use water on my hair every three to four days, and every 10 to 14 days I might use an egg on it, or some bicarbonate of soda,” Aitken Read explains。

“Last night somebody on Twitter saw a link to my book and tweeted saying four people in her office were doing it. It’s gone crazy。”

Tempted to go ‘no-poo’? Here’s your essential checklist:

1. Bicarbonate of soda. The traditional alternative to shampoo, cleans the scalp without stripping it of natural oils。

2. Apple cider vinegar. A popular alternative to conditioner, which works with the bicarbonate to restore the natural pH of the hair。

3. A bristle brush. Bristles stimulate the scalp and distribute sebum all the way down the hair shaft。

4. A hat or headscarf - for when it all gets too much。

5. Willpower. Brace yourself for a few difficult weeks – Aitken Read has heard of it taking up to three months for particularly difficult hair types to adjust – and keep your eye on the prize of healthy, glossy, lustrous hair with zero effort。