I found a few of these bomb beads for paracord, but they just didn't print nicely or work well as zipper pulls/toggles.
After a few goes at designing , I cam up with something that worked, looked good, and printed easy. I like that it hangs from zippers like the bomb is dropping.
It should come off the printer with no need for clean up.
Get your 550 paracord, cut it to a length you want. I wanted mine short and cut lengths of about 20-25 cm.
Next, you need to gut the cord. Pull out the small inner strands so that the cord gets thinner.
tie your double not at the bottom
fish one of the strands through the bottom of the bomb (small hole) and use it to pull the paracord up through the bomb so that the knot slides all the way in, and out of sight.
if the tails on our knot stick out, pull the knot tighter, cut off and fues the tails with a lighter or match.