Is this a thread hi-jack yet?
It works well when you use it on a sheet (perhaps blanket, etc.) covering the fire! It keeps the sheet from catching on fire and provides the necessary cover to keep oxygen from reaching the fire. Use a bit of a fine mist of water, on the sheet, or optionally, wet the sheet/blanket just before you cover the fire. Whatever you do, HURRY!!!
Like the Starter Fluid you gotta have a clue how it all works to your benefit. Get it wrong and well yeah, it's gonna get ugly and you will have "liquid fire" (flaming fuel floating on the water) licking at your feet and spreading like crazy.
Assuming you have no extinguisher, what other options do you have besides walkig away? OH wait, I know this one! I once used a 30 lb can of R-12 refrigerant on a VW bug fire on the side of the highway. Snuffed that fire in nothing flat. Fortunately the deadly phosgene gas cloud created by the reaction of the fire and the refrigerant floated away from our immediate area. So this method is also highly controversial (but it works well if you can pull it off without dying).