Hi, I have a question as I know nothing about chemistry, I have bought a stainless steel 45 gallon drum off a scrap dealer it says on the side that it used to contain Bn Cp nitrile for use in making Bn Cp amide, the inside of the drum still has some of this brown thick liquid here and there stuck to the sides, it is a fixed head drum with just two small holes on top so access is quit difficult, I have tried soaking for days with water but it does not seem to be moving it, does anyone know what I could use to remove this nitrile stuff and better still is it dangerous stuff, I wanted to use the drum as a beer fermenter.