How Do I Protect My Subwoofers From Possibly Dry Rotting ?

I have some 10" subwoofers that I havent used in years, and they look as if they can use some form of Lubrication around the rubber coned area. I see no form of "Dry Rotting" and I want to continue to keep it that way. Is it possible that you can apply a small amount of Armor All or some form of lubricant to the surface to protect them??