I like using a tack rag after vaccuming. It's always surprising how much more balsa dust sticks to the rag. I don't press hard, as a matter of fact, very little if any pressure is used on the tack rag. But, then I sand down to between 1000 grit and 1500 grit wet and dry and am chasing small particals of dust. Just drag it over the surface. I build in the garage, but the covering is done inside. Too much junk blowing around outside.