Peppermint Castile Liquid Soap 945 ml. Our most popular scent with a peppermint burst so pure it tingles! Scented with organic peppermint oil to cool skin, clear sinuses and sharpen your mind. Our Peppermint Pure-Castile Liquid Soap is concentrated, biodegradable, versatile and effective. Good for just about any cleaning task. Face, body, hair & food, dishes, laundry, mopping, pets & clean your house and body. ur Peppermint Pure-Castile Liquid Soap is concentrated, biodegradable, versatile and effective.