Yes, if you can get it for free, by all means, use it. I imagine the vast majority of us don't have access to that (I know I don't).
You can get used Veg oil for free from restaurants who have to pay to have it removed.
And even if you buy it in a store it is still waaay cheaper than propane or coleman fuel for campstoves
you will not be supporting those destructive corporations -see?
Is this really an issue? I've never had a propane stove fall over. They are a lot wider than they are tall, making them very stable. I don't know how a stove in a house would fall over, maybe in an earthquake or something. This is a non-issue for me.
vastly safer to use if it get knocked over or something it is not going to burn down your house, and usually puts it self out rather quickly~
It is not how much it costs per gallon but the rate that it burns at, the blue flame of propane or coleman fuel burns at a vastly faster rate - meaning it will cost 30-50% more-see.
If permaculture values are in the farming process it is way bettter than the oil industry, note the gulf oil disater and many others.
Robert Ray wrote: We have a friend that uses vegetable oil to heat his house using a "Kuma" free standing oil stove.
Though made for kerosene or stove oil, he uses filtered fryer oil he keeps in his garage to keep from gelling it has been trouble free for 5 yrs.