Never Heard That One
"Hell's Box Office?" I've heard Cinemax being called Skin-a-max, but I've never heard of the term Hell's Box Office, and neither have my two roomates. As a matter of fact, neither have any of my friends here in evangelical Cookeville.
I've lived in TN my whole life. Literally. When I was born myself, The Man, and our family lived in Antioch. After a year or so we moved to Franklin, and my parents have lived there ever since about 1986, but none of us have ever heard that term.
I can see why it would be called that, but as for actual usage, I've never once heard it.