Has anyone figured out how to disable smoke trails/plasma glow?

When you shoot a rocket, a large cloud of smoke follows it. When you shoot the plasma gun, kind of a glow or mist follows it. Both of these kind of cloud your vision, and for competitive purposes, I want to disable them.

When I first got serious about Quake III, one of the first things I did was disable the rocket trails, and it wasn't long before my rocket launcher aim showed significant improvement.

Also, getting rid of some of this extra fluff couldn't possibly be bad on the framerate. :)

Does anyone know how to do it?