Sometimes foks baffle me.
Not so much that newbies, and folks starting to take maint. seriously ask about cleaning the gas tube, mind you, but more to the fact that somewhere, somebodys uncles buddy knew a guy that works for Seal Team 19 and heard that ramming a poofy cotton covered length of wire into the gas tube will clean it and enhance reliability.
If 38,000psi will NOT blow a gas tube clear of obstructions, I would venture a guess that the Pipe cleaner ain't gonna help.
Yet the urban legend continues.
AZ,
Forget the pipe cleaners in the gas tube.
Your logic is sound.
They do NOT need cleaning, and messing with the things invites more problems than cure.
If they needed cleaning, Mother green would have Grunts wearing them out with cleaning, however I have yet to see a TM or -10 or any other reference to the matter coming from the fine folks in the Ordinance Corps.
I have seen but 1 clogged gas tube in my lifetime(Ok make that 2 but the first one was clogged by a busted wooden handled Q-tip) and it was caused by some seriously CRAP ammo, and some ghastly maintenence practices.
Best of luck!
S-28