Are you throwing away oil based wood putty you used one time, only to find it dried up when you go to use it again later? If you can dig it out with a screw driver and it has not totally solidified you most likely can resurrect it for use again.
Dig all of the product out of its container onto a clean work surface or a piece of wax paper. Use a pair of disposable gloves and start working in a few drops of common Canola Cooking oil. Work it for awhile before adding more oil. Use your thumb and edge of your index finger to break up any hard pieces.
Once you have the putty the consistency of play dough it is ready for use, or you can return it to its container for future use.
Simple, cheap, fast, and effective.