I have yet to see a test where someone took a chain apart and showed us the debris inside, or cleaned the outside of a chain then recleaned it again and showed the debris inside a chain, all which sounds like almost impossible. Now I ride on pavement, if my chain ever got to the point of looking like the test chain I'd be disappointed in my maintenance. I'll still take the extreme pressure gear oil for longevity. Still too easy to garden hose it when it needs the dirt knocked off.
Making generalities is like watching a dog piss on my car tire yesterday, and today the tire is flat, now I'm looking for that dog