I am wondering if some of that "dust" might be chemicals coming off the fabrics.
Although there is almost always lint on the lint collector in the dryer after drying a load of cottons .
How would an air purifier capture cotton dust?
Maybe keep the humidity in a comfortable range? Dry enough to avoid mildew and mold , but humid enough to be comfortable?
I never really noticed. We do keep a dehumidifier going in the basement.