When the Finally Free/Never Shave Again product is described as electric tweezers, it is because it is a tweezer device hooked up to an electrical machine. There are two types of these, one that delivers galvanic current from the item that contacts the hair, and another type that sends FM signals from the item that contacts the hair. In any case, no permanent hair removal takes place unless this system involves contact between the current, or radio frequency via direct contact of the bulge area of the follicle and the instrument delivering the current. This is because the treatment energy is otherwise dispersed into the air, or surface skin, rather than delivering the packet of energy to the hair's growth cells.
If the FF/NSA were powerful enough to work with simply sending radio frequency energy with a focused downward force into the skin, it would be thermodesiccating holes in the skin as well.