This is all Andy's workflow. I only swung the nine-pound hammer to make it into a FCPX Titles effect. OK, more like a two-pound hammer since FCPX and Motion 5 makes this so easy.
I purposely kept the particles very low so that you can apply the effect and adjust to taste without bogging down the system. When ready, go into the Published Parameters and increase the particles for its final look. Probably 2000 or higher.
You can also un-check the Build-In so that the text doesn't start with a blur-in effect. If you want to change the blur-in effect, right click on the effect in the Effects panel and open in Motion. Replace the blur-in effect with whatever you wish.
Finally, please feel free to improve it and re-post to share. Maybe someone can figure out a Rig to change the write-on effect at the beginning without opening Motion?