[Sharnbrook (Mike)]

Now don't laugh at this suggestion.

I have been considering making a Biltong drying box, (to make biltong of course), but I think an answer to your problem could be solved in much the same way. Here is a suggestion found on the www for making a dryer.

"Make your own Biltong Maker

Take a largish cardboard box and place a false bottom of cardboard about 15 cm from the bottom with a dozen ventilation holes, say 20mm diameter.
Fix 2 light bulbs underneath this, ensuring they do not touch the cardboard surfaces.
Fix a couple of steel or wood rods close to the top for hanging the Biltong. (or the camera)
Make some ventilation holes in the lid and close.
Switch on the light bulbs. The heat will rise to the top causing dry air to escape.
Within a few days you have your Biltong!"

As all you want to do is dry the camera out very gently, this would be a (basically) cost free way of doing it, and you could test the temperature generated with say 2 x 60 watt bulbs, and use higher or lower wattage bulbs to reach your target.

If it doesn't work, you can always use the drier to make biltong, or you can eat the camera.

I have also attached a picture of a similar idea, also for biltong making, to show you what it looks like.

Some folks keep cameras in a small cupboard with a light on all the time, as the heat generated will maintain sufficiently low humidity to prevent the lenses from growing fungus.

Regards, Mike