A device for promoting the clotting of blood comprises a clay material in particle form and a receptacle for containing the clay material. At least a portion of the receptacle is defined by a mesh. Another device comprises a gauze substrate and a clay material disposed on the gauze substrate. Another device is a bandage comprising a substrate, a mesh mounted on the substrate, and particles of a clay material retained in the mesh. A hemostatic sponge comprises a substrate, a hemostatic material disposed on a first surface of the substrate, and a release agent disposed on a second surface of the substrate. The release agent is disposed on the wound-contacting surface of the substrate. When treating a bleeding wound, application of the hemostatic sponge causes at least a portion of the hemostatic material to come into contact with blood through the release agent and through the substrate.