I do wish you luck with that, but I note that there's another discussion on HN today about why most blogs have turned off comments. Most of the posters agree that bots and spammers are a huge problem that outweighs whatever value they get out of it.
Some podcasts I follow have a Facebook page, and make a post about each episode. That lets them use Facebook's systems for moderation, and builds on their existing social media branding.
I'm sure it can be improved upon, especially if you can get it incorporated directly into some podcast apps.
