Cleaning oil soaked wooden ammunition boxes

[US Military Guy]

I have more than a few large caliber (81mm and up) wood ammunition boxes.

 

In my area it is pretty common to use these boxes to store tools, chains, chemicals and whatever else seems to need a bunch of oil wiped on it.

 

What suggestions do you have to remove the oil from these boxes?

 

I am a woodworker, but I usually apply oil to my projects - not remove oil.  I believe I will not be able to completely remove the oil stain but every little bit helps.

 

I have considered -

heat and paper towels to absorb the oil

solvent to "thin" the oil (and probably push it further into the wood)

cat litter to . . . (I don't know - just to try it)

soap and water to clean the box (soap and water is NOT something I would use on my wood projects, but we are talking pine not walnut)

 

NOTE:  I have not tried any of these techniques - just considered them.