It all started last year when Jennifer Reyes was trying to clean the gunk out of a sippy cup straw, reports kvue.com.

“I had pulled out a moldy, icky cup from in the car that had been there for probably 2-3 days that I didn’t know had rolled underneath the seat,” she said.

She tried cotton swabs and pipe cleaners, but the muck stayed. She then thought it would be great if she had a nylon bristle cleaner small enough to go inside that straw.

“I thought there had to be a better way,” she said.

That was the beginning of the Sippy Straw Cleaner, which Reyes designed and began selling in November. In less than four months, she is selling the nylon brushes in boutiques all over the world — all thanks to customers who found her.

“I haven’t stepped stepped foot in one store where I had to sell my product,” Reyes said. “It’s incredible.”

The cleaners are made in China and are BPA free. Reyes sells them on her website for $3.98 apiece.

She says her business is already making money even though she’s just been open for business since November.

Photo from Sippy Straw Cleaner