Yes it still works, it has hardly been used.
This should tell you enough to get started
http://reefkeeping.com/issues/2006-03/rhf/index.php
Ozone is primarily used as a water sterilizer and purifier. In simple terms it's like a UV sterilizer.
Basically you should measure ORP if you're going to use ozone in significant amounts, you can just adjust the output manually with a monitor or use a more sophisticated controller which will simply turn the unit on or off as needed.
Alternatively you can also use a small dosing rate and just monitor PH, low pH usually means high ORP while high pH usually means low ORP. This of course isn't very accurate.