Any person's input that they have a breakthrough item available should be allowed to be presented.
In general, I agree with you. There are, however, some extenuating circumstances that need to be considered in this case.
Let's begin with the fact that the First Law of Thermodynamics is one of the most thoroughly examined, carefully tested, and completely understood principles in all of human knowledge. If you're going to claim that you have found a way around it, you need a lot more than a bunch of mumbo-jumbo about "nano bubbles."
Secondly, if you actually HAVE found a way around the First Law of Thermodynamics, you are not going to announce it on some random internet forum. This would be a discovery of such magnitude that it would completely change our entire understanding of everything. Really. Everything. Albert Einstein would look like a bubble-headed half-wit compared to whoever discovered this.
This announcement would be front-page news throughout the world. COVID-19 would absolutely NOT be the top story of 2020, if this was true. Every scientist in the world would be waiting with bated breath to see the details, and duplicate the tests.
Oh, and as far as the petro-chemical companies suppressing it... There isn't enough money in the world to suppress something like this. Anyone who could actually manage to come up with a "free energy" machine would be so rich that they could buy and sell every oil company on this planet with their pocket change.
So, yes, most ideas deserve at least a hearing. In this case, though, as soon as he said that he uses saltwater as fuel, I had heard enough. The nonsense about "nano bubbles" sealed it.
There are two alternatives here: 1) The OP sincerely believes that this works, because he has been conned into believing this scam, or 2) the OP is the one trying to con people into believing this scam. Either way, it is a scam. No ifs, ands, or buts about it!