Originally Posted by HEWSINATOR
How do you clean your flask? I just got mine out, and the neck part that is all I can see is all grimey and rusty looking. Scares me about what is all teh way in there.
If the outside isn't leather or something like that, just put some dish soap inside and run ultra hot water inside and then drop the whole thing in a bowl or sink and cover it in hot water. Let it soak a while and brush the outside and cap; use a bottle brush if you have one small enough for the inside of the neck. Dump most of the water out and cover the opening, then shake it around, empty and rinse a lot.
Remember, alcohol kills germs.
Other stuff besides alcohol can corrode your flask or get the inside sticky and host growth.
Here's another site's recommendation, sounds like it would work for any musty smell issues:
To get rid of that lingering smell
Pour in some tepid water
Add a teaspoon of bicarbonate of soda and a handful of uncooked rice.
Give it a good shake