I guess you can make soap out of any fat or oil, no? Isn't that the way the Palmolive company got started? Making soap from palm and other vegetable oils?
I 'member in WWII that pushcart people would go around the neighborhoods collecting fats and oils for making explosives for the military. I still remember the cry "Raaags n old ein!" ("iron") as our local junkman trundled through the neighborhood with his horse-drawn cart. He had rigged pots and pans to noisily bang together as the cart rumbled down the street on its ironbound tires to announce his coming.
He had a large drum into which he would scoop, scrape, and pour your household greases and fats. He'd pay for the scrap metals by weight, but I don't think he paid for the grease. Maybe it was just a patriotic contribution. I imagine some of it was used to make brown soap, but a lot went to make glycerin.
He'd stop when one of the ladies called out to him and the women would come out to sell their metal scraps and old pots and my mother had a bucket of bent nails Pop had got from somewhere and we kids would come out to see the horse and pet him and so forth. A horse was a big deal for we city-born kids. Mom had to pick me up to pet him and I remember being really curious about the horse's blinders. I forget the horse's name but it was something stupidly common, like Freddie or Bobbie or Georgie or whatever.
Oh, soap. Yeah, OK, whatever.
Hey, hydrocarbons is hydrocarbons, no?
Terry, 230RN