I have a Copeland low D that needs a bit of shining up. The finish is dull with a few dark spots. Is there a preferred way to polish a brass whistle that is safe on the finish and non-toxic for the whistler? I have a couple of Sindts that could use some work as well. Any feedback is appreciated. These Copeland’s really look great when shined- up.
This should do the trick : http://www.musiciansfriend.com/woodwinds/leblanc-soft-metal-polishing-cloth-set
If it’s super tarnished you may need to go with a liquid, cream, or paste polishing compound, but that’s rarely necessary.
OTH, if you have access to a buffing wheel, you can make it look brand new in about 2 minutes 
With whistle polish? 
Seriously, any non-abrasive brass polish will work. I use SimiChrome on all my whistles with excellent results. Some purists may freak out about about the ammonia base, but it dissipates quickly in the minute quantities of occasional use and does no harm. Cloths like Loren’s LeBlanc cloth are fine with a bit more effort. Sunshine cloths (available on eBay) or Blitz cloths also work well. For occasional touch-ups, I also use a jeweler’s rouge cloth. And if you like, a light coating of beeswax or carnauba wax can help preserve your newly-polished masterpiece.
Over this side of the pond we have a skin medicine called ‘Sudocrem’. It is a paste made of fine zinc oxide powder and castor oil. It is considered ‘non-toxic’, and it also works as a fine polishing paste. You may prefer this to more conventional polishes if you are worried about toxicity.
Another reasonably benign polish is toothpaste - but I would find the minty smell too distracting.
I have used both of thee above to polish brass.
“Castor oil”, “non-toxic” both in the same sentence 
Brings back one of the terrors of childhood.
Best wishes.
Steve
Right. Ricin isn’t harmful or anything. Is it?
Feadoggie
Ooooops - castor oil was the original formulation. Castor oil does come from the castor plant which does contain ricin. However:
Wikipedia is your friend…
This is from Zubivka:
Heat a glass or two of vinegar in a pan, bring it to boiling while dissolving kitchen salt in it to saturation. I.e. keep adding salt and stirring until the salt doesn’t seem to dissolve any more. It does take a lot, like half-a-glass of salt.
Watch out, do this soup in a well ventilated kitchen: there’s chlorine evaporating.
Let it cool outside. Pour in a bottle, slowly to leave the salt deposit in the pan. Stopper the bottle for storage.
This liquid is non toxic, use it on a rag to remove stains on brass/copper whitles (I clean my Sindt with it). Wipe dry. If you dislike the faint vinegar smell remaining, wash with soapy water before drying.
I’ve been using this method since then. It works great. And if you really want the brass to shine, use #0000 steel wool after.
One thing I do different is pour the prepared solution through a coffee filter.
Good luck.
Mike
No but Ricin isn’t good for polishing whistles at all.
ecohawk
I always thought castor oil was extracted by squeezing beavers. And yes, I mean the little dam-building animal, you perverts.
I use the “Cape Cod” polishing cloths on my brass whistles.
You’re thinking of artificial vanilla.
Its always educational around here.
Pollux. That’s what I say.
Once I have mine shining to my satisfaction, I keep it that way by taking the time to wipe the whistle down with a silicon impregnated cloth after playing. It seems to help a bit. 