Gwyneth Paltrow has made a career out of selling pseudoscience on her lifestyle website, Goop. Over the years, the actress has proclaimed women should steam their vaginas, that water has feelings, and that your body holds secret organs. Mixed into these absurd assertions is her bogus detox diet and cleansing advice, all of it in service of promoting Goop’s beauty and wellness products.

Just when you thought the site’s advice couldn’t get any weirder, though, Goop started selling a $66 rock for women to stick inside their vaginas.

But here’s the really crazy part: After all the debunking of Paltrow’s fishy wellness claims over the years, including Timothy Caulfield’s 2015 book that focused entirely on her Goopshit, the jade eggs have sold out.

A “guarded secret” of Chinese royalty, used by both queens and concubines

Vagina rocks? Yes, really, vagina rocks.

According to Goop, they’re a “guarded secret of Chinese royalty in antiquity.” Allegedly used by both “queens and concubines,” the eggs apparently carry a number of magical properties. Among them: increasing “chi, orgasms, vaginal muscle tone, hormonal balance, and feminine energy in general.” The eggs also have the “power to cleanse and clear” making them “ideal for detox, too.”

In a Q&A with the magical egg seller, Shiva Rose, an actress and “clean-beauty entrepreneur,” Rose suggested women sleep with the rock inserted, if they can handle the “energy from the egg for that long a stretch,” or even walk around with them inside.

For now, let’s put aside the fact that “queens and concubines [who used the eggs] to stay in shape for emperors” may be an offensive sales pitch to some women.

Let’s instead focus on the suggestions that rocks in the vagina can balance hormones or detox the body. We turned to California OB-GYN Jen Gunter, who told us that this is scientifically absurd, and the eggs could even be harmful.

As Gunter wrote on her blog, jade is porous and can trap bacteria, increasing the risk of bacterial vaginosis or deadly toxic shock syndrome.

What’s more, advising women to stick the golf ball–size object inside themselves and walk around is also potentially dangerous, since it can cause clenching as well as pain later on during sex.

“I would like to point out that your pelvic floor muscles are not meant to contract continuously,” Gunter wrote. “Overenthusiastic Kegel exercises or incorrectly done Kegel exercises are a cause of pelvic pain and pain with sex in my practice. Imagine how your biceps muscle (and then your shoulders and then your back) might feel if you walked around all day flexed holding a barbell? Right, now imagine your pelvic floor muscles doing this.”

There are appropriate ways to strengthen the pelvic floor. Jade eggs are not one of them.

Now, Kegel exercises — the contracting and relaxing the muscles of the pelvic floor — can be beneficial. They can help support the uterus and bladder, particularly after those muscles are weakened with pregnancy, childbirth, or a surgery.

But as Gunter told Vox, “There are appropriate ways to strengthen the pelvic floor. Jade eggs, especially the method described, meaning wearing at night or walking around, are not the way.”

Instead, she suggested women ask their gynecologists about how to strengthen their pelvic floor muscles or even work with a pelvic floor physical therapist if needed. Some may opt for Kegel weights made with medical-grade silicone or plastic, which are safer than a porous rock.

Paltrow and her Goop marketing team deserve credit for imbuing rocks with magical feminine properties so alluring that online shoppers emptied the store shelf. As Caulfield, author of Is Gwyneth Paltrow Wrong About Everything?, told Vox, “[Their success] speaks to the power of celebrity endorsements in the face of science, the power of Paltrow’s brand to make [jade rocks] sound like they’re credible.”

Goop’s popularity is also a reminder of the uphill battle for advocates of scientific evidence. Even if debunking doesn’t have an immediate impact, getting the science on the record is important in the long run, Caulfield added, as is teaching critical thinking skills. We have to find ways to help people call Goopshit when they see it. And the jade rocks are most certainly a lesson in Goopshit.