Provided herein are methods of drawing out oils and/or fats (e.g., hydrocarbons) from a solid material (such as, e.g., metal or rock, e.g., a hydrocarbon bearing geologic formation). The methods comprise fumigating the solid material with a gas containing chlorine dioxide, thereby drawing out oil and/or fat from the solid material. The methods can be used, e.g., to clean solid materials used in industry and to enhance the recovery of crude oil and/or natural gas from petroleum wells.
