The Chasam Sofer states that we cannot assume that a medical treatment that was tested successfully on a Nochri will also be successful on a Jew. The Chasam Sofer does not state that it will most certainly be ineffective.
I do not profess as to being the expert on the Chasam Sofer. For further inquiries on this matter, please read the Chasam Sofer and direct your shailos to your local Ultra-Orthodox Talmid Chachom. (This shall serve as my final statement on this matter. For all further inquiries relating to this issue directed toward me, please re-read the preceding paragraph. Yours Most Sincerely, Volvie Gumpel)