Forget the freezing altogether. Forget the microwave also.

Scrape off all of the fat and connecting tissue from the skin. Wash the skin in warm water and Dawn that has a couple handfuls of borax in the mix. Rinse in clear water and dry. Store in zip-lock bags or plastic containers with moth balls that contain paradichlorobenzene as the active ingredient. You can store in the bags with borax if you want. Use only borax to absorb any fat that remains. Never use salt.

The borax in the wash will kill bugs. The moth balls will kill both bugs and eggs should there be any left after a good washing. The moth balls also prevent any new infestations. Moth balls that contain naphtha as the active ingredient only repels the bugs.

Jerry