The Pao facial muscle exerciser device (MTG, Nagoya, Japan) is clinically proven to train the muscles around the mouth. It involves simply holding the device in the mouth and rocking it by nodding the head, such that the bilateral balance weights begin to swing. This device is fully sanitized and in like new condition. See this NIH article for documentation of the benefits of the Pao facial exerciser: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5888959/