I agree with his statment. The problem is that most people using Pothos or some other plant do not..
1.) Use enough of it.
2.) Throw enough light at the plants.
From what I have seen, lots of people who try this just throw one sprig of Pothos in there, put it by a window, and hope all their nitrates will magically disappear. That isn't going to cut it. You need lots of plants and lots of light but it will work like he says. I do maybe a water change a month in my 300G and can never read more than small amount of N03. And, I have one of the biggest waste producers you will ever see. But I also have lots of plants but more importantly, lots of light.