How do I properly clean the transducer/ultrasonic membrane?

Clean the transducer/ultrasonic membrane with a 50/50 mix of white vinegar and water applied on a cotton swab, then wipe off with a damp cotton swab. Never touch the membrane with your fingers, as the natural oils in skin can damage the surface. Never submerge the base in water or any other liquid, and never use detergent or scrape the membrane with a hard object. (Page 9)