Saw this on YouTube (my favorite station):
Did you know?  You can make your own silica gel packs for pennies...buy a cat litter whose ingredient is ONLY silica chloride.  Then using paper coffee filters, or pre-made empty tea bags used if you have bulk tea, or a small square of old cotton sheet material:  cut coffee filter in half, put 1 teaspoon of the silica into each half, fold each half up and staple securely shut.  Put one packet into anything you want to be sure to stay dry.  They are reusable if you put in a warm oven for a short period, they will dry out and work again. 

So maybe you all know about this?  There are occasions when packing food and other items for camping when I think a silicon gel packet would be excellent to be sure things do not collect moisture.
Such as dehydrated food items, crispy crackers or cookies, and so forth....

RE: The "Do not eat" warnings.  Turns out the warning is because the packets you find in bags of food, etc, are considered a choking hazard.  The silicon gel is not toxic in itself so if ingested, drink plenty of water and it will pass through the digestive system with no bad effects.   8-)