Ever buy a new pair of shoes or a bottle of vitamins and notice those little packets filled with moisture-absorbing silica? Before you toss them away, think about saving them for your kitchen. The writers at TheKitchn.com keep the packets inside cast-iron pans in the kitchen cupboard. Since cast iron is never really thoroughly washed, some trapped moisture can live in the seasoned cookware. A packet or two of the silica gel helps prevent rust and degradation.