A while back I bought a Silkstone from Wanderer. A year later he played it and noted that it seemed sweeter and purer than he remembered. Shortly thereafter I washed it thoroughly and the tone deteriorated, also it made squeaky sounds. I was just harder to play.
Going on the theory that my accumulated goop had improved the sound, I decided to try spraying in WD 40 to replace the goop I had washed out. It seemed to help a little, at least temporarily.
Then I tried hair spray. The sticky, high hold kind that turns a hairdo into a DOT approved motorcycle helmet. I applied it through the “window” hole. At first the improvement was minor, but after successive applications the improvement was very noticeable.
Note: Light sprays are best. Let it dry and give it another light spray. I’ve given mine about 10 good applications so far and it works like a charm.
um… what exactly whas the goop 
that you washed from your whistle?
Puhleeeeease----do we really want to know? 
Just (morbidly) curious. My whistles have remianed goop free (some are decades old)
My Trombones on the other hand, tend to cultivate goop at a rather prolific rate. Especially if I am playing for a broadway show. Long rehearsals mean you eat in the pit. Goop abounds. 
I feel a little queasy…
I don’t have whistle goop, but I do have whistle fuzz. I always carry a Dixon in my laptop bag, and it builds up a velvety layer of fuzzy bag dust that really does seem to mellow and soften and round the tone. When I wash it or when I lose it and have to replace it with a new one, I can hear a difference until I get a new layer of bag fuzz built up. Actually, I carry two now – one to play and a back up that’s just riding around collecting bag fuzz.
I don’t know what the ingredients of bag fuzz are, but when I do bother to clean it, it doesn’t appear to be mold or fungus. It’s not gross or anything; it’s just bag fuzz. And it does make the whistle sound better.
Geeeze!.. You really played it?
Were there Guinness worms living in your goop? I have had them in my whistle.
MarkB
WOW!! Thank You!! This improved my Burke so much, I actually like the whistle now. It had so little back pressure before that I had tried tape, clay, toothpicks etc. and nothing seemed to work. I used two separate sprays of hairspray and the whistle is singing without one gasp for air.
I will add hairspray to my gig bag spares kit. Thanks for a great tip!
Linda 
This sounds interresting, BUT: what if you try it and don’t like the results, how do you clean it out?
Before trying anything else, I would try dishwashing soap and warm water, dunking in and out many times and then rinsing with strong stream of water. Hairspray does wash out of hair, I think. I would try this washing on something else before I put hairspray in my whistle. I would hesitate to use solvents of any kind. There is glue holding some things together in there I believe.
But I am no expert, that’s for sure.
I applied it through the “window” hole.
presumably blocking off the windway first? 
Brian
Aww, what’s a little chemical poisoning in the name of art? Painters are
always smearing their fingers with heavy metals and breathing unhealthy
fumes… surely you aren’t suggesting that whistlers are any less dedicated
to their art?
–Chris
Aww, what’s a little chemical poisoning in the name of art? Painters are
always smearing their fingers with heavy metals and breathing unhealthy
fumes… surely you aren’t suggesting that whistlers are any less dedicated
to their art?
I was thing it would increase back pressure by narrowing the windway. maybe not desirable. Then again it might help prevent clogging.
Brian
No, I didn’t block the windway first. Maybe I should have. In this early stage of research I don’t know whether the beneficial effect was from hairspray in the whistle head or hairspray in the windway. I suspect the former.
Glad to see someone else got some benefit from this.
When playing this same Silkstone in a loud session, a regular audience member noticed the difference and asked if I had a new quieter whistle. The Silkstone now lacks the sharp bite that carries across the fiddles. I’ll be using this one for small sessions only in future. It always seems that when you gain something you lose something too.