A friend of mine was trying to convince me this stuff was valid today
They play off the ignorance of innocent saps, the only successful thing an HHO generator does is part fools from their money.
You may tell them that electrolyzing water into hydrogen and oxygen requires the same amount of energy that is released when they are combined again. However, they have an answer for you: a mysterious way to get water separated with less energy than normal electrolysis requires.
The mysterious magical acronym? PWM.
I would have thought that Pulse Width Modulation was not enough of a vague term to get people to buy into this nonsense, but apparently it still mystifies people into a head-nodding, I-see-the-emperor’s-clothes, money-spending attitude.