Atiria Paranihi and Ainsley Brunton are selling the Kangen machines (left) in Whanganui for about $4000 a pop.
Whanganui woman Ainsley Brunton was sick of drinking Coca-Cola but couldn't stop.
"I'd go through two 2.25 litres bottles of Coke every day. That was my normal diet."
Then a cousin in Raetihi told her to try Kangen water and she was hooked straight away.
"I feel a lot more alert — it's given me more of a zing within my body."
Now she's selling the Kangen machines in Whanganui, doing demonstrations from her home and trying to get people interested via Facebook.
That is despite scientists saying the water has no proven beneficial effects.
The Kangen water machines regulate the pH (acid or alkaline level) of the consumer's tap water.
A company called Enagic is providing the machines to Brunton from Australia.
She said she gives people free samples of Kangen water from her machine and then tries to sell them the device.
How much do they cost?
"That varies," Brunton said.
"What I like to say rather than how much does a machine cost, I'd like to ask how much does our wellbeing cost?
"How many people have got a TV worth $2000 — how much of that is helping their wellbeing?"
Brunton admitted they weren't cheap. The machine on her kitchen counter would go for about $4000. Enagic's website has more expensive options.
A flier for the Kangen water claimed it had been proven to have "therapeutic health benefits for more than 150 diseases including cancer, diabetes and cardio-vascular disease".
Enagic claimed that Kangen water's benefits were down to the fact it restored the drinker's body to a more alkaline state.
But a biological scientist at the University of Waikato, Dr Alison Campbell, said that was nonsense.
"That's not possible — your tissue pH is very strictly regulated by your lungs and your kidneys and you can't actually change it," Campbell said.
"If you do drink alkaline water ... it may well change the pH of your urine because your body will flush out the excess, but you can't actually change your tissue pH from drinking it."
Shaun Holt, a medical doctor and adjunct professor at the School of Biological Sciences at Victoria University in Wellington, studies products that become popular — like Kangen water.
"Basically, it's pseudo-science. To a non-scientist it may appear plausible," he said.
"They use terms like ionisation ... it sounds really scientific. But you can't change the pH of your blood."
He believed Brunton and others promoting the product were being irresponsible.
"She's not doing good. She should do her research, she should talk to experts.
"I have sympathy for people who buy the machines ... you get a lot of desperate people.
People with cancer, severe pain, but they're being given false hope. There's not a single clinical study to show that it works for anything."
Ainsley Brunton's sister, Atiria Paranihi, is also selling the water machines.
Asked why they were promoting a health product not backed by any clinical studies, Paranihi said that didn't mean it wasn't beneficial.
"For me ... word of mouth. I'll go off what other people say. If it's working for someone, I'm at least going to give it a go," Paranihi said.
The sisters cited multiple anecdotes of people's health improving after converting to Kangen water.
"Personal testimonies have been the most evidence that's come forward," Paranihi said.
However, Holt said they shouldn't be putting out medical products and making claims if they don't know what they are doing.
"You wouldn't get away with that with any other industry."
He said the machine was riding on the success of the placebo effect.
"The more sort of exotic and weird something is, the more sort of placebo effect there is. They say if people try this water you're going to feel better and most people probably will for a few weeks.
"Science cuts through all that. It counts for the placebo effect, which dies off pretty quickly."
Enagic was approached for comment but had not responded by press time.
The donated monitor helped an 89-year-old patient to venture outside on walks.