I use to have an Alloy boat, and condensation
was a real problem, as the boat was closed up on its mooring
during the week, trapping the moisture inside. Mid-week I used Calcium Cloride, and it worked well. It stopped that mouldy smell that occurs on closed up boats. I bought some household moisture absorbing packs from the supermarket (to get the containers) and then used Calcuim Cloride purchased from pool shop. Went through about 2 cups per week. It was good for a closed up boat, but not really and option for clothing
areas like draws and cupboards, and definiately no good if underway.
The kitty litter appearance desiccant mentioned by Blue Stocking, I may be wrong but think is clay desiccant, and is great for use with clothing
(no chemical smell). It is non-corsive, so also good for use near elctrical gear
. It can be re-charged in the oven
at relatively low temperatures (from memory 160 degrees). I have used it in house but not on boat. When I first purchased it, I thought they had given me kitty litter