Dr. Sherber does not recommend ultrasonic cleansing brushes because, quite simply, it is impossible to prevent bacterial build up in the bristles and is impractical to replace the brush head daily.  However, FOREO’s ultrasonic cleansing device is a breakthrough because it is doesn't use a brush head and is instead made from 100% waterproof and non-porous silicone.  Not only can it be cleaned effectively with soap, as porous bristles cannot, but it can even be washed in the dishwasher.  Sherber+Rad was one of the first retailers to import this from the U.K..