I vacuum my bobbin area with one of those hand held vacuums it works pretty good. The nozzel isn't big enough to do a really good job but it does get into places you cant reach with a brush.
I wasted money on an attachment for my vacuum cleaner made just for sewing machines and it was a big hassle and did not work that well. Cost 10 dollars at Joanns sewing center. Dont buy one.