When I was a child, my Granny had one of these. It’s essentially a plastic tub that you fill with water with a small heater coil and a vibrating motor. The heat and vibrations actually serve for a pretty decent foot massage–as well as I can remember. Granny’s “secret ingredient”, being a retired Avon lady, was a capful of Skin So Soft–which, allegedly, served as a decent mosquito repellent as well.
A capful of “Triple S”, the hum of the motor, Nickelodeon cartoons, a Jell-O Pudding Pop in one hand, and a Fla-Vor-Ice in the other: Georgia summers in the early 1990s.