It isn’t going to damage your engine. I’ve used it before with no issues. If it was going to damage your engine most likely by now it would be off the market due to so many lawsuits and such. Hopefully you haven’t recycled that perfectly good oil.
There's a lot of products on the market that are absolutely terrible that continue to set sales records every year. The oil supplement market is no exception. They are constantly dodging the Federal Trade Commission over false claims hence why so many keep the marketing nonsense as vague as possible so they can't substantiate the claims. The companies invest a lot of money into marketing to beat around the bush as much as possible. Many of them have been caught, pay their fines, and then re-release the same product with slightly more vague labeling. Zmax, STP, Slick 50, Duralube, etc... they've all been busted at one point or another.
Also, there's no application where any of them are actually beneficial. They're a solution looking for a problem. There's nothing in any of them that will provide any benefits over the base oils and additives already used in modern API oils. If a certain oil is inadequate to your needs, then you need to use a better oil, not a supplement.
Take this for example.... I could fill up a bottle with tap water and slap a label on it calling it a mild solvent that'll remove light dirt spots and stains. It could say it's safe to add to any common degreaser and will not harm your hands, your floor, or clothing. You could market it as a solvent that's safe if consumed and no need to keep it out of children's reach. Guess what? It's 100% factual... it's bamboozling bull****... but it's factual.