The most complete way to remove oil from wood though the equipment is a little on the pricey side but it works incredibly well, it requires a re-sealable thick walled metal box and a mid level vacuum pump with a method of heating the box continuously to about 25oC 77F. The wood is wrapped in cloth and surrounded by Fullers Earth but Cat litter will also work to soak up the oil. The wood is left in the reduced warm atmosphere until the oil stops traveling to the surface leaving the wood virtually oil free.
