I use kerosene heaters mostly to heat my house, and because of the cost of kerosene, they have been quite expensive. Back before 2000, I could get 20 gallons for 20 dollars. Now it is 5 gallons for 20 dollars. Does anyone know of cheap alternatives that would work in a heater or furnace that is designed for kerosene? I was thinking along the lines of waste cooking oil, though I would not know how you could convert it for use. You are only supposed to use k-1 kerosene in those heaters.