I am not sure of the drinking properties of turpentine, though I have heard of down and outs drinking it. About 1740ish when gin was becoming a serious problem in London, there are references to turpentine and sulphuric acid being added to gin. Whether this was done to make it taste better, give it a kick, or to dilute it with cheap adulterants I don't know.

As regards the origin of ratarsed, I have put a feeler out with a CAMERA friend. They ought to be experts on drink related matters.