high humidity storage

I have a whitetail buck shot in Wisconsin and the owner lives in Costa Rica. He told me that another taxidermist told him that there was a method of tanning to help the mount withstand the high humidity in his country. I called McKenzie Taxidermy Supply and asked if they carried any products that would aid in this process and they said they have never heard of it. Has anyone else ever heard of this?

Thanks.

Doug