Blue Power Carbolic Soap Mild disinfectant soap containing carbolic acid, a natural compound extracted from coal tar. Once widely available in the United States and the most common disinfectant cleaner used in hospitals, real carbolic soap has all but disappeared from stores. Remembered by many older Americans as the household soap of their childhood, real carbolic soap is often sought after by many simply for its nostalgic natural scent. By killing bacteria, it acts as a mild deodorant when used as a body soap. Many people report it is great for clearing up acne. Tough on germs and grime, some folks say carbolic soap has a rugged, leathery scent, while others think it has more of a medicated fragrance.