Does anyone have experience/recommendations regarding the in-case humidity control packs made by Boveda? This system was recommended to me by a violinist friend.  It's a sealed pack that fits inside a fabric pouch, and either absorbs or gives off moisture to keep the humidity in the case in the 45-55 % RH range.  Where I live in Canada we have very humid summers, and very dry indoor air once the furnace comes on the the winter.  I'm thinking of trying it in a double case where I keep my Morse an