rowuk

Metal can be left underwater for an almost indefinite time without damage. Felts need to be replaced if they have been soaked and I wouldn't leave corks under water for more than an hour or two.
Believe me, what may be growing in your horn already exists on earth and has not destroyed any other life forms!
If you can get the stuff out yourself, the horn will be clean. Getting it checked by a pro will make sure that it is in the best playing condition possible!

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Whenever I feel blue, I start breathing again.