There are different types of bentonite clay and Ms Beesley said she wanted to find an alternative to the products already available in New Zealand
"We couldn't get a clay in New Zealand to match the specs we were looking for and we ended up with one of the world's top quality products," Ms Beesley said.
"We had to buy a tonne which was a huge commitment."
Ms Beesley and her partner Euan Haycock started building a workshed behind their Mount Bruce home in September last year, which is expected to be ready next month.
Health stores in Wellington and Petone stock the product, as well as Ms Beesley's The Self Heal Clinic in Carterton.
Ms Beesley said she not only uses it with her patients but has also used it on animals and Vetcare in Masterton also stocks the clay.
"We started out with almost no sales to having it fly out the door," Ms Beesley said.
"We have a joke in the clinic - anything that's red, raw, itchy, scratchy or won't heal, we whack clay on it."
The company is also building a new website as the old one was not compatible with mobile devices.
Ms Beesley said a large amount of Purely Earth's sales have been made online.