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

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

Short and simple.