Through Twitter, producer and director Jim Michaels revealed that the explosion in this episode "went way too large" and they had to rebuild part of a back lot in the set for almost $20,000.
At one point, Ellen tells the boys to "kick it in the ass". This is a tribute to Executive Producer/Director Kim Manners who passed away in 2009. He was fond of saying this phrase before a take to encourage the actors. A similar tribute occurs in Mulder & Scully Meet the Were-Monster (2016), where Kim was also a Producer/Director. In that instance, a tombstone is shown with Kim's name, dates of birth and death, and the epitaph is, fittingly, "kick it in the ass".
The episode's title refers to Dante Alighieri's The Divine comedy: "Abandon all hope, ye who enter here" is written above the gates of hell.
When Castiel tells Dean that he has found Crowley, Dean replies, "Okay, Huggy Bear. Just don't lose him." He is referring to the confidential informant from the 1970's TV cop drama, Starsky and Hutch (1975).