It’s common advice from mom, your favorite household expert, and even Frank Reagan on Blue Bloods: “You need only two tools: WD-40 and duct tape: if it doesn’t move and it should use WD-40; if it moves and shouldn’t, use the duct tape.” The $2.5 billion dollar company is based in San Diego, so the multi-use product’s not made by elves or anything. But the precise formula is secret. That’s left inquisitive types to float many ideas about possible magical ingredients. A few under consideration over the years have included fish oil, wax, chlorofluorocarbons, kerosene, and something or other that cures arthritis. WD-40’s headquarters are usually just amused by the conjecturing, but they do correct myths that are unsafe. Has anyone come close? WD-40’s not saying, but here are a few more hints:

WD-40, the fisherman’s friend?

Among its 2,000 or so applications, WD-40 can lubricate air conditioner blades, help remove broken keys or erase crayon from most surfaces. Police once used WD-40 to remove a burglar in the buff from an air conditioner, too, and there are dozens of true stories like that. But the company has come forward to dispel the rumor that the product helps catch fish. The story got going when multiple customers told WD-40 that rubbing WD-40 on lures and hooks helped them catch the big fish. This started the idea that fish oil was WD-40’s magical ingredient. Nope on the fish oil in the formula, the company has publicly stated on its website. It also added that no one should use WD-40 to catch fish due to water quality concerns. But it did confirm that WD-40 protects lures and hooks from rust and corrosion.

Wired’s take on WD-40 ingredients

The staff at Wired had a lab evaluate a can of WD-40 and came up with a chemical alphabet soup of ingredients. “Seriously. WD-40 is mostly a mix of baby oil, Vaseline, and the goop inside homemade lava lamps,” was Wired’s first conclusion. They also spotted numerous alkanes-hydrocarbons in the formula, including decane. It helps WD-40 keep from freezing in the garages of those four out of five American households that own WD-40. They also spotted the alkanes Nonane and Tetradecane, the isomer Dimethyl Naphthalene and Carbon Dioxide.

But there’s still plenty of doubt about the formula for this “secret sauce.” And WD-40 takes great pains to protect the proprietary formula, especially since it has never been patented. When they had to move the formula to a new bank vault in 2018, they did so with an armed guard. Oh, and the formula traveled in a suitcase handcuffed to the CEO’s hand. He kissed it goodbye. “It’s written on a spiral notepad and it is actually the notebook of the chemist at the time,” WD-40 CEO Garry Ridge told 10 News San Diego. “I don’t know if I’ll ever see it again.”

How to use WD-40

Along with questions about the formula, some wonder about all those many applications making the rounds of Pinterest and the household tip sites. But even the super-sleuth myth-busting Snopes website concluded that WD-40 had lots of uses. When asked to fact-check a particular list of 45 WD-40 uses, Snopes collaborated with the manufacturer to arrive at a solid 22 proven uses of WD-40. Highlights included protecting silver from getting tarnished; loosening stuck zippers; repelling pigeons from balconies with its aroma, and lubricating prosthetic limbs. Snopes also found 23 items on that list that weren’t true. WD-40 cannot clean guitar strings, for example, or keep flies off cows or relieve arthritis pain when sprayed on arms or knees.

And hey, here’s good news: WD-40 also removes all traces of duct tape, according to Snopes. You know, in case you had just two choices and still made the wrong one.