Charles
I use a fan-circulated de-ioniser in my darkroom and find it an essential piece of kit. It helps to cut out a ton of retouching later on, and keeps the air alpine-fresh on long printing sessions.
Another technique I've seen is to attach a shiny plastic sheet to the wall, then before a dev session, give it a vigorous rub with a dry rag to build up a positive charge, the idea being that the dust sticks to the sheet, and away from your drying negs. It works very well apparently.