I never said it couldn't work. It's not working by burning the hydrogen. could be as simple as throwing sensor values running it a little leaner than it should be. As long as it remains in range, there will be no code set...
Put it on a scanner with the setup, and then turn it off. see what sensor values change. you should see a change with the O2 sensor and possibly fuel trims if somthing's happening as you say it is.