Simply put, the AMNS is "A MAZE" and "A SMOKER', hence "A-MAZE-N-SMOKER"
What you can't achieve with chainsaw chips in a foil pouch, is a continuous smoldering burn during cold smoking, for 8+ hours. Yes, you can get smoke form damp sawdust in a foil pouch, but there needs to be a heat source to keep the sawdust smoldering. Once ignited, the AMNS follows a "MAZE of Sawdust", while producing a very nice TBS. The AMNS was originally created for "Cold Smoking", but guys quickly adapted it for use during Hot Smoking.
The sawdust is nothing special, other than I grind it to a specific size, so it burns well in my little gadget. Too large or too small sawdust particles, and it will not burn very well. Chainsaw chips are too big to burn in it.
Lots of different ways to generate smoke, and as long as you've got a "Lifetime Supply" of apple and hickory chainsaw chips, you doing good!