Debating A Heretic Antisemite?

What's to gain by debating a heretic? Rabbi Yaron Reuven says the Jewish Sages forbid debating a Jewish heretic, and a debate with a non-Jew has to have a purpose. It's obvious Adam Green won't do TeShuva, and neither will his followers, so nothing good could possibly come out of debating an atheist Nazi with a Jewish name.