Sorry for the misunderstanding. The program I watched profiled the profession of men who cleaned up rotting carcasses to render for fat and commented about the smell. When I wrote that I was laughing at myself, thinking of the groundhog hit in front of my house and the raccoon I’d just found dead in my backyard, and that I missed out on the opportunity to experiment with other animal fats. Humor is a personal thing and frequently a mismatch that doesn’t connect with others. I meant no offense.
None taken. I'm one of those who appreciates context (I need to know or I can go way up the wrong mountain). I might have an idea of the show you're referring to. Dirty jobs that no one wants to do. As for your own referrence, I'd pass that up. If you've never seen what's in some carcasses of certain animals, you should keep that imagery unseen. Trust me.
We small-scale makers here on SMF have the luxury of using edible fats to make our soap, but that isn't the case for other people. Soap has historically been made from low-value or inedible fats. The old soap making manuals I've read from the mid 1800s often have long sections explaining how to segregate and store more desirable fats apart from the less savory fats as well as how to clean, bleach, and deodorize fat before it can be used in soap making.
The soap making trade in the British Isles (and elsewhere, I'm sure) used fats from less-than-savory sources because edible fat is more valuable to use as food and to make higher-value products. As an example, candle making consumed most of the higher value fats (for example the "stearin" harvested from tallow). The soap makers had to figure out how to use the less valuable fats (for example the "olein" from tallow or cottonseed oil in the US).