Here is a guestion from a Mike Rowe interview I found.
1. Forbidden jobs:
Q: "What dirty jobs did you always want to do but the network or producers wouldn't let you do? (too dangerous, inappropriate, so on)," asked SSJStarwind16.
Rowe: "The segments I was most interested in doing but found the most resistance around was that of a rendering facility. ... the Mob is still involved in a surprising number of rendering facilities. Why the Mob has such a rich history in garbage-related industries and rendering-related industries is a conversation beyond my pay grade. I only know how relieved I was to finally find a rendering outfit that was not owned or operated by the Cosa Nostra.
"That facility was in Northern California. And they were called North State Rendering.
"To this day, I'm impressed with how brave they were in their decision to let us provide our viewers with an unvarnished look at what it takes to turn a dead cow into several hundred pounds of chicken feed." http://www.cnn.com/2014/11/12/opinion/mike-rowe-somebodys-gotta-do-it-ama-questions-answers/