I have an air compressor in my darkroom so I use that first on a low setting. I then use "IT Cosmetics Heavenly Luxe Mega-Fat Fan Brush" and yes, that is really the name of the brush. Its the softest brush I have personally ever felt first hand and its a wide thick brush so its great for getting dust off of statues. Here is a picture:
Honestly, it feels like a baby bunny's fur its so soft. It will pick up a lot of dust just with a couple strokes. I have also used some of the anti static brushes that I use for cleaning my negatives. Those can work really well too.