[FreedomoftheHills]

glycerine is a common enough ingredient, but Idunno if it exists in large enough quantities

These folks sell it in gallon jugs:

http://www.kvvet.com/KVVet/productr.asp?pf_id=51804&RefCode=Froogle&URLCheck=1

And you can probably go down to your local farm CO-OP, ranch supply place, or anywhere that sells veterinary or horse-related supplies and get it the same way.

You don't really need much for the firestarting reaction, though, and can find small bottles at many drug stores.