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Ever since I saw my first Hall flute, I’ve wanted a clear whistle - and twelve bucks for that clear acrylic D is pretty cheap.
OTOH, one thing that seems a little odd is that he has a link to the Whistle Shop on his web page, yet a search of Thom’s site turns up nothing from theis Mr. Brooker.
Why don’t you buy one and review it for us gg.
Daughter has a Crystal Flute and says at times it looks yukky as her drool and moisture can be seen when playing. She’s promised to buy me the Poppy Piccollo for birthday though and I’m not saying not either. It looks lovely. 
Don’t care much for the clunky looking connector, but for the serious WHOA afflicted, it may be worth $12.
For those not adverse to recorders, Yamaha makes some TERRIFIC clear soprano recorders in transparent pink, blue , or green. They are very cheap ( under $10 US) and play phenomenally well. If you buy them in all colors you can mix and match the sections for a truly funky looking multi color look.
Closest I have come to making a clear whistle is a very early Busman in Maple, with a clear fipple: I found a piece of lucite rod by the roadside while walking, and thought it might be a good substitute for the wooden fipples I was using at the time. Looked pretty cool for about a year or so, and then the lucite started cracking internally, which looks pretty cool in it’s own right.
All I can say is yuck
(mental picture of slobbery shaft)
eww!
Whistle-through thistles?
- Wow, who makes 'em?
- With these, what hurts more, cross or half-fingering?
spiffy, now EVERYONE can see how much spit ends up in your whistle. 
I have a really cheap clear plastic r******r that I was gifted, and though I’ve never stooped so far as to play a tune on it, you can see the inside misting up as soon as you start to blow. Play for a minute or two, and mist condenses to drool.
I’m with the “let’s keep drool private” camp.
What is the world coming to.
Today See through whistles…Tomorrow see through underwear 
Oh, it’s been done…
Whistles and flutes are vile enough without having to see the intimate processes that lead to such drippage. As posted otherwhere, I am still working on a discreet design for a flute diaper. Also in the works is a prototype diaperette for whistles. Serpie ain’t got nuthin’ on me.