Great tip! Grease lamps have been used since prehistoric times. I believe there is some evidence that cave paintings done at the end of the last ice age may have been illuminated by shells with twisted moss wicks, filled with animal tallow. The Romans made small lamps that looked like a gravy boat, that burned oil with a wick. A more modern version is the "Betty Lamp". Made of tin, more or less in the shape of a heart, They were filled with cooking grease, bacon fat, tallow, almost any soft burnable grease. Hung from a lightweight piece of chain, with a woven wick, they were smokey, stinky, but did give off a little illumination at a cheaper price than candles (which at the time were either tallow or beeswax).
I like the double usage idea of the Crisco. You can light your kitchen while you make a flakey survival pie crust (or fry chicken). Once, just for fun, I found that I could make a candle out of a Chapstick and pocket lint. Without a source of light, most activities grind to a halt at sundown. I just finished butchering three deer from our whitetail season, and the amount of white, waxy tallow was amazing; inch thick slabs of it. Tallow candles are softer than beeswax or petroleum wax and have an unpleasant smell, but before the advent of petroleum products, natural fats, oils and waxes were highly valued. I have a large supply of modern and beeswax candles, but the Crisco idea is another one to tuck away for when it might come in handy.