Can I suggest another way of keeping your deacs looking good.
There's a product called
Renaissance wax that friends in the museum world put me onto a while back. They use it to prevent surface decay on a really surprising array of materials. I've used it on bits and pieces from swords & rusted 'dugups' to a Bren gun and it basically does exactly what it says on the tin without doing any harm to the artifact itself, & lasts for years.
Quite expensive but worth every penny if only for eliminating the need for using grease or oil on things stored in the house.
Cheers,
Adam.