I have heard that people out west used to use powdered cayenne peppers to stop bleeding. Apparently, it has something in it that helps blood to clot. People would spread it over a bleeding wound and bandage it to stop the blood loss. It was at least occasionally effective, since doctors used it quite a bit on the frontier.
I don't know if it has any antiseptic properties, but being able to stop bleeding isn't a bad quality to have.