The DryGuy AC/DC has been in my car for the last 3 years and when I hit the road it comes with me. I’d love to see it the size of the Circulator but that’s my only complaint.
Put it in the toes first to warm that up and then move it back to the heels after. It’s slow drying but it works and doesn’t make any noise. I can leave it in all night and the boots are dry in the morning or mostly dry after a long drive. I’d rather have a car adapter for the 6″ Circulator but I haven’t found that. So it works and still has a place in my car.