Rendered animal fat is excellent for making crispy (and tasty) roast potatoes, but also good for greasing the pan for Yorkshire puddings. Duck or goose fat is the best.
I wonder if what you actually heard was someone referring to kerosene by its UK name (paraffin).
Rendered fat is great for cooking, but if you are going to dispose of it, keeping it in an old soup can, as mentioned above, is a good idea. Keep the can in the freezer so the fat congeals and just toss the frozen block in the trash on pickup day.
Avant garde sculpture!
Make a bust of Czarcasm!