I have a large fireproof gunsafe.  I access it infrequently and have used silica gel to dehumidify it but have been unhappy with how frequently I have to recharge them.  The humidity is usually too high at 50%.  I also store powder and ammo in the safe.

I have been considering drilling into the safe to put an electrical cord in so I can put a goldenrod dehumidifier inside.  Anyone with experience with these who can tell me how they work?  The safe manufacturer was concerned since the safe is pretty airtight that the goldenrod would create somewhat of a sauna effect if the humidity cannot vent outside the safe.

Thanks for your comments!

Many safes have a hole or a spot where a hole can be punched out to allow an electric cord to pass through.  Check the lower back portion of the interior for this.  It's only about 1/2" wide in diameter.  Place the dehumidifier at the bottom of the safe, run the cord through the hole, then attach the plug to the cord and plug it in.
Humidity isn't a big problem where I live, so I run my dehumidifier rod on a timer that runs through hourly cycles - 1 hour on, 1 hour off, etc.  I haven't heard of the the "sauna effect", but using a timer might help with that as well.

ETA:
I also use Bullfrog spray on my firearms.  It's a vapor corrosion inhibitor that creates a layer of protection against moisture.

Can you tell I'm a little paranoid when it comes to rust?

Go with the goldenrod - "pretty airtight" isn't airtight. Those silica packs didn't wet themselves.

50% humidity is actually a very low reading. My hygrometer rarely drops below 60% or 70% and I've only been using a single goldenrod for the last decade with zero rust on any firearms.

Ditto what M4-guy said about placing the GR in the bottom of the safe. The heated air rises and circulates throughout the safe. Don't know why it works, but it works.

I've lived in high humidity areas most of my life.  I keep a good coat of oil/clp/etc. on my firearms and have never had rust.

The goldenrod is good insurance but isn't really necessary, especially with only 50% humidity.  Just keep 'em lubed and you shouldn't have any problems.

I like the goldenrod. I just let mine run all the time. They only draw like 15 watts or so.

Goldenrod.  There are others that may be cheaper.  All it consists of is a low wattage heater.  A light bulb of the same wattage will do EXACTLY the same thing.  In AZ there is humidity when you run your swamp cooler.  50-60% sometimes.  Trust me, the Goldenrod works.  I was lucky to find them in a clearance bin at Jumbo Sports in South Carolina on a Field uh....excursion.  $8 ea and I bought two.  It must have been a screw up.  New in wrapper.