Hmm...very interesting. It's got a bit of a snake oil feel to it because it's so simple, but he's not selling anything, so who knows?
After looking through all his examples, it looks like the basic idea is to cut a groove from the main combustion chamber into the thin "squish" area. On our heads, you'd probably want two grooves - one starting between the exhaust valves, and one starting between the intake valves.
Like this Celica head, which was the only 4 valve example I could find that was similar to our heads: http://somender-singh.com/content/view/42/37/
I wonder though, if a sharp edge on the groove might make for a hot spot in the combustion chamber and make the head less boost-friendly? Maybe if you smoothed out the edges...