I was doing some framing on a window and found my wood putty dried out.

This is what I did to rejuvenate the putty.

Flatten or spread out the putty, then add 2-3 drops of corn oil and knead together.

2 minutes of doing this saved me a trip to the big-box hardware store.

Does it have to be corn oil? 

I would be afraid that a food oil could go rancid. What about a finishing oil like linseed oil, Tung oil or walnut oil?

Another problem for me is that my wife is hyper about food, and won't allow corn oil in our home.