I suspect that he's not going to convince some people unless and until he can do something practical with it, namely produce usuable energy. If he could produce usable energy, on a net energy basis, it would be kind of hard to say that it was an illusion. Energy doesn't just appear out of nowhere.
I don't believe he needs to prove it can do anything useful although that would be great. As a scientist he's not necessarily interested in the end product. He's more interested in seeing if there's a new undiscovered nuclear process here. That alone would rewrite the science books and probably win him a Nobel.
If this is achieved(cold fusion), life as we know it will change dramatically......Kind of like when oil was discovered.