What about silicant or silicone desicants? They keep away moisture you know. I' ve put several of them inside my dvd cabinet.
Yes I believe Dehumidifiers in certain extend may help in preventing this negative effect on our precious treasures. It will never hurt to try esp if your collections (like mine) are stored in closed cabinets, wardrobe, drawers, bookshelf, leather bag, storeroom, etc. It's suitable for clothes, leather, camera, computer, audio & video equipment, etc.
You may want to try a new product named
"Thirsty Ele" which cost about P300 per bag, can be reusable for 100 times! Each last for 1-3 months, natural & non-toxic, absorbs moisure 2 times faster & deodorizes by neutralizing smell rather than covering it.
It's the best way to lower humidity naturally by removing dampnes, sweat vapor, humid gems, mildew and odour. Keeping dry will reduce airborne bacterial.
For double protection measure esp in those expensive limited edition boxes with tight spaces, you may also want to try using Desiccant Silica Gel as per blitzkrieg's suggestion. For me, I'm using both...
Let me know if anyone is interested & I could bring back a few extra from Malaysia.