It's recommended to use the same fragrance oil that came with the reed diffuser to maintain the intended scent. However, should you want to refill your diffuser with a different fragrance oil we recommend following the following steps: Pour out any remaining fragrance oil in your jar. Wash your jar with warm soapy water. Rinse your jar thoroughly with clean water.  Allow your jar to air dry overnight. Once your jar is completely dry you can pour in your new fragrance oil.  If you would like to explore our Reed Diffuser Refill range click here.