Open the dryer door, locating the ductwork and removing any screws that hold it in place. Clean all surfaces inside the dryer with a non-abrasive cleaner such as a vacuum cleaner and bucket. Pour 1 cup of boiling water into a spray bottle and mist the inside of the dryer. Close the dryer door and allow it to vent for 10 minutes. Open the dryer door again and use a wire brush to clean any debris that was left behind.