Desiccant is a substance that is very hygroscopic (adsorbs moisture from the air) in nature. There are different kinds of such desiccants available, however, only a few would serve your purpose.
Absorption: >30%
Crystal & Beaded
White, Blue & Orange
0.5 gm – 500 gm
Absorption: 70%
Natural Clay
1 gm – 1 kg
DMF Free, MIL-D-3464E
Calcium Chloride
100% – 300%
125 gm – 1.5 kg
Converts to gel