New Jersey-based masseuse Dorothy Stein is known as the back-biting masseuse because one of her controversial technique involves sinking her teeth into her clients to “tenderise” their muscle and promote blood circulation.

Dr. Dot, as rock legend Frank Zappa nicknamed Stein in the 80’s, when she used to massage bands just to get into shows, was encouraged to use her teeth as a massage tool by her mother, at a very young age. She was only five when her mom asked her to give her a massage for the first time. However, her hands weren’t strong enough at the time, so her mother asked her to bite her instead. It apparently worked, because over four decades later, Dorothy Stein is still using her chompers to tenderise her clients’ muscles and promote blood circulation.

Believe it or not, it wasn’t her unusual “bite massage” that made Dorothy Stein so popular with A-list celebrities. In the early 80’s she started offering free massages to popular bands backstage, and that’s how she made a name for herself. Def Lepard and The Rolling Stones were among her first clients, and even though she didn’t charge anything, she was able to build an important network of contacts.

Stein only began charging a fee for her massages in 1994, but by that time she had become so famous among musicians and Hollywood celebrities that people didn’t mind paying for her services. Even today, the back-biting masseuse has big names like Kanye West, Katy Perry or Simon Cowell on her client list, and charges around $150 per massage session.

The celebrity masseuse started adding the bite to her arsenal around 30 years ago, but admits that not all of her clients opt for her unconventional technique.

“Naturally, I ask the client if they want to try it first,” Dr. Dot told Refinery29. “And then – before adding any oil – I bite the whole back up and down, in a very fluid motion, bit by bit, avoiding any bones. I do the neck and shoulders, and sometimes the glutes, too.”

“I take big bites, obviously not firm enough to break skin, but firm and deep enough to grab and ‘tenderise’ the back muscles, warming them up for the real rubdown that follows,” the masseuse added. “I’ve never hurt anyone doing it; it’s actually divine for the client, as it’s a sensation they’ve never experienced before. They’re marching into the unknown and putting their trust in me.”

Dorothy Stein was recently on British television ITV’s This Morning show, where she gave a live demonstration of her biting massage technique. Viewer feedback was mixed, with some people commenting on Twitter that it was admittedly weird to watch but they couldn’t look away, while others couldn’t get past the gross factor.

“Why would you want a stranger’s mouth and saliva on your back? OMG NO,” one person tweeted.

While Dr. Dot claims that her unconventional bite massage promotes blood circulation in a similar way to cupping, not everyone is convinced that it is harmless. Dr. Holly Phillips, author of The Exhaustion Breakthrough, raised some concerns about the risk of infection, if Stein accidentally overdoes it with her biting. “About 10 to 15 percent of human bite wounds become infected by bacteria. There is also the potential for transmission of viruses like hepatitis B,” she told Billboard.