Laura Harnett, founder of cleaning essentials brand Seep, has revealed how she built a million-pound sponge business in her 40s, secured a listing in Tesco, and why she believes age gave her an unfair advantage. Speaking about her journey, she shared the harsh reality of winning over supermarket buyers and how backing an "unsexy" idea paid off.
Why starting in your 40s helped
Harnett said she used to think she had missed the boat to start her own business, feeling too risk-averse and worried about her mortgage. But after getting an idea for a cleaning essentials business – sponges and cloths – that no one else seemed to have spotted, she read a Harvard Business Review article noting that the most successful entrepreneurs actually start their businesses in their 40s.
By that age, she explained, she had learned over a long career how to make good decisions, trust her gut, and read people. She had acquired a broad understanding of the skills an entrepreneur needs, from pitching to recruiting, reading a P&L, and negotiating with suppliers. She also had a little capital behind her, allowing her to back herself in the early days.
But the biggest advantage, she said, was her network: "People I had helped out over the years, former colleagues, team members and bosses, former suppliers and customers, all of them now in roles where they can help, often in exchange for nothing more than a sponge. I wouldn't have got to where I am without my network. It's been an absolute superpower."
Backing an unsexy idea
Harnett said she was increasingly stripping toxic products out of her home and switching to things better for her health and the planet. The green and yellow sponge, however, she couldn't find a plastic-free alternative to. She couldn't understand why no one else had disrupted the category – the answer, she said, became clear: "It's the most unsexy product category there is."
The first few people she mentioned the idea to were shocked, questioning how she could go from a director at Selfridges to setting up a sponge business. Investors felt the same, with nobody wanting to put their name behind a plastic-free sponge brand, preferring a vitamin or beauty brand instead. But she kept coming back to one thought: if somebody else did this in five or ten years and she hadn't had the courage to do it herself, it would be one of her life's few regrets. She was also convinced that the humble sponge is one of the products most UK households touch multiple times per day.
Now, she said, she is glad she backed an idea that no one else could see: "We're growing fast, we don't have a direct competitor (yet), we're able to bring innovation and energy into one of the most tumbleweed aisles in the supermarket."
The biggest lesson learned
Reflecting on the biggest lesson so far, Harnett said she wished she had known how long it would take to get Seep onto supermarket shelves. Having started her career as a buyer, she thought her idea was so good that everyone else would see it too. It took five years of emailing, showing up wherever she thought she might find the right buyer, and building a solid set of evidence that the product would actually sell, before anyone would give her a meeting.
If she did it differently, she said, she would be more patient and focus on getting undisputable evidence on rate of sale first, proving that customers loved it: "That would have saved me so many ghosted emails. Now I know what evidence you need, plus what level of audience you need to bring, so it's impossible for them to say no. Then retailers will have absolute confidence it's going to sell on the shelf."
Was Dragon's Den worthwhile?
Harnett described appearing on Dragon's Den as one of the best decisions she has made since setting up Seep. The casting team had been in touch a couple of times over a couple of years to see if she would be interested in applying, but she couldn't think of anything worse than being exposed in front of millions of people, with her accounts and numbers picked apart: "Anything could go wrong and it could have been game over for Seep."
Then an opportunity came up to be listed in Tesco, the UK's largest retailer, and she needed a way to drive brand awareness fast enough that people would actually pick the product off the shelf. She asked the team if she should risk it, and everyone said yes: "It was 100% the right thing to do."
Since airing in January 2025, she believes the show has delivered over £1 million in equivalent media value, not just from the initial airing but from footage used in ads since, and the support received from Deborah Meaden and Trinny to win competitions, deepen relationships with retailers, and reach their audiences. Ten percent of people still say they first heard of the brand through the show: "It's the biggest unfair advantage you can get for your business in the early days. You just need the guts to do it, and to manage the emotional fallout afterwards."
