I save the plastic liners from cereal boxes to reuse in several different ways. I use them to line the bottom of paper grocery bags which I use for garbage sacks under the kitchen sink. They are great to keep wet or damp items from soaking through to the bottom. Those items might be wet paper towels, wet tea bags, or some type of moisture that leaks to the bottom of the garbage sack. Another great use is to put chicken bones in them and then tie up the open end of the plastic with a twisty. That works great to keep the smell contained within the liner instead of stinking up the trash. If you think about it, the liners are designed to keep moisture out of cereal, so they can be used all sorts of ways to keep out moisture.  Or they can be used in the reverse way to keep moisture inside.  Maybe you have another use for them.  If so, I’d be interested in hearing about it.