From the previous responses above, I must be in the "Overkill Zone". Over the years I have read posts from other forum members who use other techniques (i.e. gun socks). However, I agree that moisture and humidity can cause a lot of problems with our firearms, especially rust, pitting, etc.
The links below are for pictorial purposes only. I have a Liberty safe that included a goldenrod which was my starting point. Then I added a rechargeable mini dehumidifier:
[ame]https://www.amazon.com/gp/product/B000H0XFD2/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1[/ame]
When the crystal color changes from blue to red, plug it in an outlet overnight and you're back in business.
I also added an electric dehumidifier in the "Man Cave" to ensure that I have minimized the moisture damage risks.
[ame]https://www.amazon.com/gp/product/B00UWP07LK/ref=oh_aui_search_detailpage?ie=UTF8&psc=1[/ame]
I live in north Georgia. We don't have the high humidity issues that other forum members have, but in the summer or after several inches of rain (even in the winter), you'd be surprised how quickly that tank fills up.
Bill