Yes, an explosion with a new scripted effect would probably work. In the script you can check for the reference its running on, and if not the NPC's of your choice, then kill and disable.
If you follow the laser weapons projectile back to the effect, you will see how it works. Namely, look at the critical effect type.
Weapon >WeapLaserRifle look at Crit Effect.
Actor Effect >LaserDisintegrationFXSpell
Base Effect >LaserDisintegrationEffect
ScriptName >LaserDisintegrationEffectScript
An explosive would be this path:
Weapon >WeapGrenadePulse look at Projectile.
Projectile >GrenadePulseProjectile
Explosion >GrenadePulseExplosion look at Enchantment
Object Effect >EMP
You could then make a Base Effect like the laser rifle above to attach your script to the Object Effect, just like an Actor Effect.