Dessicant is used to keep electronics and other items dry when shipped or stored. The most popular dessicant is made of silica, which is light, small and dustless, and can draw in several times its weight in moisture--which makes it convenient for placement in shoe boxes and any other parcel or area where small size, light weight and maximum cleanliness is needed. You can reuse these packets, rather than purchasing new ones. To do so, you must simply recharge them by making them lose the moisture they've collected.
Turn your oven on to 150 degrees Fahrenheit. You do not need to preheat it before moving to the next step.
Place the packages of dessicant on a clean, bare cookie sheet. Place this in the oven on the middle rack.
Set a timer for 15 minutes and check the packs. They may need five or more minutes, but most should be dry by now.
Remove the cookie sheet from the oven and place in a safe place to cool. Allow the dessicant to cool completely before handling it.