I have never used canned air on any machine so I am clueless as to whether you should or should not use it.
They sell a cool sewing machine cleaning tool package that fits on your home vac. The kit has adapters in it so that it attaches to the home vac and then converts so you can hook up little nozzles and brushes. It allows access to those tiny places in your machine. I bought it when I bought my Serger. Works great!