I think there was another tutorial for this (on redtech maybe?) but it involved a Switch event and a bunch of other junk you don't actually need.

Toggling particle emitters is simple enough but might not be obvious to someone who's new to RF's events.

1) You have a particle emitter.
2) Create a Particle_State event and link it to the particle emitter.
3) Create an Invert event and link it to the Particle_State.
4) To turn the bolt on, you just link something to the Particle_State and activate it.
5) To turn the bolt off, you just link something to the Invert and activate it.

Short and simple.