Hydrogen injection is what you are talking about (not sure if that is what the OP is talking about) but i applied for a co-op job at a company that made those for trucks.
Its a huge box, that you pour water into, and it uses electrolysis to seperate the hydrogen from the oxygen.
i think it's prettymuch like water injection where it lets you run more timing/boost at the same fuel/air temp to make more power. on a N/A engine, it will barely be needed. now if it is supercharged/turbocharged, whole nother story, but it's easier to just use methanol...

BUT, i dont think that's what the OP was talking about.