When you use distilled water and 100 percent pure essential oils, cleaning needs will be minimal. If you experience mineral buildup or allow water to stagnate in the unit, more cleaning may be necessary. You can safely rinse the bays with water, taking care not to get the electronics inside the base wet. You can also use a soft cloth dampened with vinegar to wipe out the unit and remove buildup or run the unit with a few drops of vinegar to clean the internal workings.