Of course. That's what I mean; there's no evidence that it's anything special. (Which isn't an issue either.)
For all we know, her hair would grow that fast without anything on it. It's not like it's a scientific claim or measured in any way. People who hear that would think, "damn, that sounds incredible", when it's just questionable marketing. I'm not bothered by harmless cosmetic products assuming they're not super overpriced and finessing people out of their money (compared to people practically selling water as cures for cancer), but it's still in the realm of snake oils.