I bought a used harmonica on e-bay (bad idea). Now I guess the previous owner must have been a smoker because the instrument stinks. Rather disgusting. No way to play it like that. Is it possible to clean and/or disinfect a harmonica without making any harm to it?
Humidifier - filled with disinfectant (such as diluted household cleaner like the not-so overwheling pinesoll of your choice not a ton it will be over powering) setup the harmonica in front of it where the vapor flows through it, and let-er rip for about an hour, take away the humidifier and dry it out with a fan for about an hour. should be good to go. May have to do it more than once depending on how bad it is. I had to do the same thing… my grandfather turned me on to the humidifier thing… worked like a charm. I used pine-sol lemon scented half and half mixture with water. Of course… it takes several times of plain water to clean out your humidifier though 
I also ran the harmonica on plain water vapor once just to kinda clean out the ‘flavor’.
There’s probably a better easier way out there somebody will tell here, but that’s my experience.
Take care,
John
Howdy,
A belt sander will do the job pretty quick, with the added benefit of more whistle practice time 
Best,
Dave
thanks guys
There’ve been times I soaked them in an oral antiseptic. This is surely u nrecommended by wiser people, but the longest-lived harmonica I have, underwent this.
well then there you have it. I always wonered if it would be okay to soak one in liquid solution or not, but Granfather always say: “He not sure either, so best to do it like a vapor like your own breath”
I wondered if the older harmonica innards would swell or weaken, never to return or not, so apparently not!!! HOORAY!
Talk about easier. I’d go that route.
Take care,
John
If the comb is wood, you would have to think about whether soaking it in a water solution would cause trouble. I’m not a harmonica expert, so I don’t know.
However, you can soak wood in alcohol without hurting it, so one step might be to soak it in alcohol and then let it dry thoroughly. (If anyone knows different, please correct me.) Alcohol might be more effective than water based preparations in removing the smoky residue.
Best wishes,
Jerry
Taken directly from one of my books:
"Sometimes the wood in a traditional harmonica will dry out. This may be due to age, abuse, or excessive playing. Soaking makes the instrument more airtight. It also allows a stronger pressure of air that makes the reeds easier to bend.
There are several disadvantages to soaking and extreme caution must be used before any instrument is soaked. An instrument should be soaked only when it is totally useless in its present condition. In that case there are three options: throw it away, use it for spare parts, or soak it and hope it will be playable.
To soak, immerse it in warm water for a couple minutes. Do not use other liquids bcause they may contain harmful chemicals that could destroy the more delicate parts. Once a wood combed harmonica has been soaked it must continue to be resoaked before each playing. Drying out causes the airtightness to disappear and worsens teh condition. it can also make the painted surfaces peel and the wood comb warp or crack. It promotes corrosion in the metal plates and tends to damage the reeds.
After the instrument is soaked the wood will swell or raise above the level of the metal plates on the blowing surface. If this excess wood is not removed, it can injure your lip. Remove it carefully by filing with a fine file or emery board; or shave it carefully with a razor blade.
Remember that the manufacturer’s warranty will not be accepted if the instrument has been soaked."
I think I have that same book. 
Yeah, a wood comb will swell pretty good, especially a Hohner Marine Band, and will do this even if you play it a long time, from the breath vapors and all that. Caveats are well heeded. That said, some of the old-time bluesmen always boiled their harmonicas before breaking them in.
The front man in our band also plays harminica as well as guitar. He’s got four or five he plays fairly regularly. I’m not sure about the care and all that of a harmonica, but when asked how much his cost, he said he can pick up new ones if hhis ever get damaged for something under $20 a piece.
I assume there are some that can go for a bit mroe than this but is it honestly worth all this trouble for a harmonica? Unsure and curious…
Bri~
I’d say, price-wise, they are in the same range with whistles, all around, but a little more particular and high maintenance.