The third one - involving the use of electricity - presumably generated on board as you drive - to generate hydrogen and oxygen by electrolysis of water - also carried on board - which is then added (by whatever method) to the combustion process to produce higher output power and/or increased torque ....... is just pure drivel.
Adding hydrogen is arguable, but not outrageous.
I didn't see anyone is saying that there is no such thing as hydrogen fuel or vehicles - the claims made about oxyhydrogen are what is at issue - and yes we MUST understand new technology so as not to be hoodwinked by those who would fake the science