EvaUnit01
Kept you waiting, huh?
I'm actually not even sure if Joseph knows about it. Most of what he taught Jotaro was an echo of what Lisa Lisa taught him and Caesar 50 years ago.Zeppeli, and by extension Jonathan, was able to use Hamon to detect and track Jack the Ripper back in Part I. Does Jotaro know about this technique, or can we have him stumble upon it somehow?
So, no. Jotaro doesn't know about it, and I don't see any reasonable way that you could have him "stumble upon it" in this situation.