You're using particleView's fullscreen mode, right?
The way you're doing it is the way that at least a few other people are doing it, based on feedback I've gotten over the years. We've considered doing a live performance tool based on particleIllusion, but there are a couple of other projects in front of it right now.
Yes, I'm using fullscreen mode. Turning erase on and off adds some possibilities as well. Hiding the pointer is a dilemma because it makes it difficult to see were you're drawing but it is better without a visible cursor.
I use VJing software called REsolume, which in its latest version uses OpenGL for rendering, and I wonder if it might be possible to develop an FFGL (Freeframe OpenGL) plugin to display PI emitters within that environment? That would be pretty awesome.