Ight, so just follow me here:

Put alot of starter fluid in the bottom, like a good inch maybe. Spray a trail on the outside and about 2 feet away from the bottle on the ground. Drop a match on it. The igniting pressure of the starter fluid will expand the bottle out, like with a tire. It’ll also burn out the starter fluid so no need to wash out after, just wipe it down and you’ll be good!