Sorry, aruanan, but just because it doesn’t contradict any known physical law doesn’t mean that it can be employed for any practical benefit. You need to consider the energy required to excite the vial of salt water.
Did you watch part 2 of the video? If so, you saw a bright yellow-orange flame. Do you know why the flame was that color? It wasn’t the burning Hydrogen...it was the sodium from the salt water. Guess what happens after the sodium gives off those yellow photons? It recombines with Chloride and forms salt (just like two H2 and one O2 recombine to form 2 H2O). Tell me, sir, how do you get rid of all that salt? Or are you just going to leave it to build up inside whatever engine is used?
It ends up taking more energy to make the pretty flame than what is produced by that same flame because of all the other things going on.
Let me say it this way: if it takes X amount of energy to go from 2H2O to 4H + 2O, then recombining 4H + 2O to get 2H2O gives off exactly X amount of energy. But that assumes a perfectly efficient reaction chamber. I hope someone can eventually come up with one of those, but thermodynamics laws are notoriously difficult to overcome.