I have a golden rod as well. It doesn't move the air around. It just brings the temp in the safe up a few degrees from the outside of the safe. This has the side affect of drying the air out. I monitor the humidity in the safe and the golden rod seems to be doing the trick.
I prefer the golden rod to the bake type dehumidifiers since they're zero maintaniance. As long as they have juice, they're working. I check the humidity/temp every once in a while to make sure that they're still good and that's it. No having to remember to recharge the dehumidifier box.
Edit: Didn't realize that you could recharge though the outlet. Good point about the possibility of loosing juice. Generally we don't lose power long and when we do, I have a generator. Of course, that would be no good for long periods with out power. My only question would be how long would something like that last w/the humidity level that high?