When I was a teen almost forty years ago, I worked for a couple of antique dealers where I did everything from move furniture to restoration work. I worked with a couple of guys that I thought were ancient who were just amazing when it came to doing things like replacing missing gingerbread and splicing new wood into 100 plus year old planks on damaged pieces. We used Murphy's Oil a lot.
If you are worried about Murphy's, you can get some boiled linseed oil and use that. It is not petroleum based and it will refresh dry wood. Be sure that you are using BOILED linseed oil as regular linseed oil will be sticky to the touch and once it is on, it is hard to get off completely. Boiled linseed oil is about the most unobtrusive liquid that you can use on wood that won't have negative side effects.