So I came up with this way to make a very strong rope. The cool thing about it is you don't need *any* tools to make it.
Step 1: Materials
Figure on approximately 2 bags per foot of rope
Step 3: Tear through the middle
You can use your fingers and tear them vertically from bottom to top very easily as demonstrated in the video.
Step 4: Optional tool: scissors
Step 5: Make strands
Tear a tiny hole in the side near the bottom seam.
Thread the handle of another section through the hole you just made.
Thread the body of the other section through it's own handle you just passed through.
Pull it tight.
Repeat until you have about 5 or 6 half bags connected together into a strand about 6 feet long.
Make at least 2 of these strands to get started. It helps if they are contrasting colors, but not especially necessary.