because it sounded cool? sort of "Parsley, Sage, Rosemary and Thyme" kind of thing. i have used bamboo and pine as firewood to boil water before.
No, Phi. It's another example of misplaced punctuation messing with the sentence structure.
Plumb and pine are both intended to be read as third person verb forms.
"Plumb bamboo and pine" is clearly a reference to the fact that bamboo, being a hollow solid, can be cut and arranged as piping for latrines; however, being not ideally suited for the task, the user will end up pining for proper indoor facilities.
Worthy advice indeed and the tie-in is obvious in that water is freely available; however fire to provide hot running water is another level altogether.