Well, CM may be a bit exited over it, but he's right. The "nitrite phase" severs any relationship between nitrate and ammonia. Efficient nitrate reduction, or "Natural Nitrate Reduction", NNR for short, is a very tricky subject. It's kind of the holy grail for saltwater hobbyists, as we try our best to keep nitrates at zero all the time. It can be achieved through cultivation of anaerobic bacteria, and/or proper balance of O2/CO2 exchange between floura and fauna. A person should have a very thorough understanding of aquarium chemistry before getting into this area. Fooling around with anaerobic bacteria and deep substrates is very dangerous; the smallest mistake can cause the tank to crash.
A more reliable method if you have the room and the cash, would be to plumb up another tank, somewhere above the main display tank, and use a powerhead to pump the water up to it, then gravity back. The increased water volume would slow nitrate build up. The larger the auxiliary tank, the slower the build up.