I found an old strop in a box that used to be my Grandfather's. It is pretty dry and hard but there are no cuts or gouges in the leather. The only thing I know about it is that it is pig skin. I don't know how old it is, or when it was last used (I never saw him use a straight razor). I'm just wondering if there is anything I can put on the strop to soften it up and make it suitable for stropping. I thought about Neatsfoot oil But I wanted to get some opinions first. Also would I treat both side or just the smooth leather side. There is no linen, just leather. Any suggestions would be appreciated.

Thanks