Look, some tobacco simply reached the end of its useful life
The method yields a cooler smoke and also reduces the heat strain on the back wall of the chamber around the air hole, that place most susceptible to scorching in a bent pipe
While the system is designed for self-reliance, it is not entirely closed
To take it to the next level, however, mix this with C&D's "Cube Cut Burley" which kicks the performance up to medium-to-strong and slightly lessens the sweetness, which while less than seemingly every other aromatic, when reduced allows more of the natural tobacco to shine through
It feels like he's leading up to something clever, maybe a surprising twist, but no
Hematology Am Soc Hematol Educ Program 2011:96-103, 2011