Sophie Jones stands in front of a planeload of passengers, and wishes them a "lovely flight". She is not trying to humiliate herself. She is practising rejection therapy. Filming and posting the interaction will also attract millions of views on TikTok.

Jones's stunt looks like elaborate self-sabotage. It is, but for a purpose. Rejection therapy is a self-help trend that claims to build resilience, boost self-confidence and promote risk-taking by encouraging participants to seek out situations where they will be told no. The trend has blossomed on social networks like TikTok, where #rejectiontherapy has millions of views.

Now, the practice could be making an appearance at work as businesses try it out with employees, and striving individuals seek to get ahead in their careers by taking on the lessons of rejection.

On TikTok, increasingly outlandish rejection pranks include videos of creators asking to make a train tannoy announcement, or dancing in a public space. One asks a passer-by for a $100 loan. "Do you think I could have a tour of your flat?" another enquires. Some viral videos show brutally awkward rejections; many see individuals met with an unexpected yes.

Those adopting the approach to help their career confidence take a more sober -- if not necessarily less anxiety-inducing -- approach.

Colleen McFarland, a management consultant from Chicago, says rejection therapy was key to growing her business. Self-promotion was her biggest challenge after she went freelance. By challenging herself to be told no at least once every day by a stranger, she was able to build her soft skills and confidence to find a new client base within six months. "It's that powerful of a philosophy that [it] can . . . help everybody," she says. The experience even inspired her to write a book.

Fear of rejection is a real issue at work. A University of Houston study found workplace rejection contributed to burnout, reduced wellbeing, and dissuaded employees from seeking new opportunities.

Tackling this has been part of rejection therapy from the start. The approach was created in 2009, when IT worker Jason Comely came up with a card game to help with anxiety he developed during a divorce. The game offers players ways to be rejected once a day for 30 days, with prompts including asking a stranger for their business card, or your boss for a raise.

In 2016, entrepreneur Jia Jiang bought the game and developed it into a brand. After the popularity of his Ted Talk, "What I learned from 100 days of rejection", he now coaches teams on overcoming fear of rejection, and has shared his approach with employees at Deloitte and Google.

The approach has its critics. Unlike exposure therapy, which carefully "exposes" individuals to things they fear and avoid, rejection therapy has not gone through clinical trialling.

Ann Francke, CEO of the Chartered Management Institute, says attempts to build confidence at work are "not new", and "tried and tested ways to grow people" remain the most effective routes to do so. They might include stretch assignments, applying for promotions, or formalised management training. CMI research showing 82 per cent of managers have not received any formal training suggests this is still too unusual.

Jiang says his most successful intervention was with a real estate sales team, which called past, prospective and existing clients with the explicit aim of getting rejected. The company subsequently "had the best quarter of their whole company's history" as sales skyrocketed.

Tina Weinberger, HR business partner at Splunk, says hearing Jiang speak helped her switch careers. "Being the only Asian woman in a group of middle-aged high-powered executives, I started to doubt myself," she says; the ideas of rejection therapy prompted her to network by reaching out to strangers. That enabled a shift from sales to engineering.

Still, many experts remain cautious. Paul Grantham, a clinical psychologist, teaches a course on rejection therapy for mental health professionals, and worries about the lack of structure in the version trending online. "There's a lot of tools that are valuable and useful, but you need guidelines about how to use them."

In his own practice, Grantham focuses on specific problems, identifying triggers for a patient's aversion to rejection and building up exposure in an incremental manner. Without this, he says, "it's either going to be ineffective or even worse . . . it could be quite damaging to self-esteem."

Could rejection therapy transform workplace risk-taking?