So just been researching potential dry chamber designs and solutions and ran across some information on dessicant paper products which seem to be a very good solution to getting a rechargable dessicant inside the camera near the sensor. There is this company in California that makes strips of rechargable dessicant paper (silica) and special camera anti-fog strips:
https://www.sorbentsystems.com/dessic_paper.html
scroll down to the camera anti-fog strips.
This same sort of product is available locally for GO-Pro cameras here:
http://www.ebay.com.au/itm/12pcs-GoP...-/311402797047
there are a few ebay sellers of this product.
I will be ordering some of these to start testing as internal camera dessciant.