If you're not fluent in lua (I'm still not), you can do the same thing in .ini with an MOSRotating with DeepCheck = 1. Much simpler and completely lag free.
First time I saw the "Worms" effect was in numgun's AAL bomb pack; he had a terrain bomb that relied on a highly-concentrated but short-lived burst of particles. Later, he improved the effect with his TTB Rocket, using an ADoor which "swept" around in a circle. Then Shook used the aforementioned MOSRotating method in his Pelian Army PlanetKiller.
I made a small mod that simply removed all explosion effects besides the terrain wipe from the PA PK (I kept the cool delay flash):
I also made a grenade version (with no delay flash):
Here's the file:
Check out some of the comments I made near the end of the .ini. PM me if you still need help (though I might not be able to respond until the 16th).