Can reeds get residue by: playing in a stuffy environment, a dusty environment, cigarette smoke, campfire smoke, etc…?
Does it affect the behavior and tone of the reed and how much? Is the residue noticeable if you were to take a look at the reed?
I’ve had reeds display signs of giving up the ghost - collapsing back D and weak tone etc. On closer inspection the inside of the blades had become dirty from too much pub air - visibly dirty on the inside of the lips. I would then give the insides a fine sanding by inserting some 400 grade emery paper between the blades, pinching with my fingers and withdrawing the paper, repeated for the other side until the dirt was gone, and the reed was rendered playable like new once again.
Interesting!
I once put an air-filter (piece of cotton) on the air inlet of the bellows
and it was coloured dark after some time in smoky places
hi pipers,i played the pipes at caernarfon castle in wales for about 6 years or so.as you know wales is famous for it’s rain and when i could not play outside which was often i played in the basement under the eagle tower which is about 20 yards from the sea.i was making reeds a lot but i had a beauty in my chanter and did not look at it for a couple of years,just played it.one day i had to look at it to make a small adjustment and to my astonishment the reed was completely coated in cuprous oxide caused by a reaction from the sea air and the copper bridle,it was green and furry from bridle to tip but still sounding great and my reg and drone reeds were the same.it seems that the fungus had only attacked the outer of the reeds and left the inner parts clean,very weird,the chanter reed carried on for another 18 months and then died as do all reeds eventually but the reed was so furry,green and with blue spots as to almost unrecognizable,amazing what a piece of cane will endure and no i have not been taking acid(not for the last 40 years anyway)hwyl fawr,allan.
Same thing happened to me. Robbie Hannan offered this tip:
Put a piece of paper between the lips, squeeze as you pull the paper out. Do this a couple of times. You can normally see the dirt on the paper.
It’s pretty disgusting but at least I’ve not had to do it much since the smoking ban.
I’ve heard tales of pipers pulling lumps of tar and dirt out of the bag before…
Would it affect the tone of the drone reeds?
I’ve recently watched a Finbar Furey video where he talks about his bag exploding onstage, and dirt and “fag” dust blew everywhere…
Oh, yeah. You betcha. I saw a chanter reed this summer that looked like was packed with pine tar and cat fur. (And I promptly took it home and gave it to a friend who needed the measurements. I thought about sterilizing the tin I transported it in … it was MANKY!)
Speaking of fur, I’ve caught a bit of fluff in my drone reed before. Jim Wenham claimed it was more like half a cat, but I didn’t believe him. 
Nonetheless, I do inspect my pipes whenever the cat goes missing now …