One of the problems with the original is that the light strings just clumped at the bottom. While I could spread them out a little in the bottle, over time, they would compress at the bottom again. The solution I came up with would also aid in making the bottle appear more full, as if it was full of Tabasco Habanero. I would use wired garland.

This bundle was cheap, I think found at Target on sale.

It has a rigid, probably steel, wire at the core, and is wrapped in reflective red plastic with a star design.

The reflective red would help add volume, and create more reflections of light, and the stiff wire would keep the wires from settling to the bottom.

I cut segments to match the length of each of the strands, and wrapped the wires around it.

50ft was actually not enough to cover the length of all the strands, but I found it was more than enough volume to fill the jug. So some of the strands that I inserted near the middle I left off the garland wire, and other strands I bunched up the light strings on the garland wire to make them shorter.