My SO uses shaving soap. The mug is just an ordinary coffee mug (the original mug he had fell apart from age [Big Grin] ) There aren't any extra soaps at the moment, but they are not easy to find. They are probably about 3 inches across and 3/4 inch thick. You might be able to find them at Walgreen's or some such drug store. The coffee mug is too deep, he says, and needs to be shallower. I'm not sure if this is helpful or not. Oh, and he likes unscented.