Did he mean water injection only or water mist elctrolysized in a per spark plug chamber then inject that? Or will anything water qualify?
Some feel that water injected into a cylinder exposed to 1000's of watts of spark power does elctrolysis and steam all in one wack. Others use stacks of plates for better control to do their electrolysis. Either method should work since both consume about the same electrically power. I have not tried them all yet.

It works.