I have seen packets which absorb damp....maybe try to seal the lids to the bottoms with duct tape??? How about regular clay cat litter in old stocking legs you've cut off!! That absorbs moisture! ... View related article.
first of all, wrap each item VERY well and store in a cool place if you must make them up ahead of time...frequently at dollar stores they have a variety of clear wrapping stuff used to wrap baskets...do you have to use plastic? will it be so full that plastic is nec. to keep it from falling out? why not tissue paper? why not clear garbage bags? ( and a pretty bow) ... View related article.
If you use a glass jar to store grease in be VERY careful pouring hot grease into it...it could shatter...especially if you keep it in the fridge!! ... View related article.
try making a spray from dishwashing liquid and water, and spray on there, if that doesn't help, try vegetable oil ( canola oil etc) and cayenne pepper. ... View related article.
I agree with the plywood, we did this for an old loveseat we had which was still in good shape, but you disappeared into it......still works well!!! ... View related article.