It should work. And if it's a never-ending process, then instead of calling it in the controller, you'd have to call it right after local_import in your db.py. You would also need to turn the ImportScript into a singleton and make sure it only gets initialized once because you don't want to spin off a new process for every request.
I've never tried it like that, but assuming you have a never-ending while loop or equivalent to process the queue, it should run continually. I would probably recommend using time.sleep() in there just to make sure the process doesn't take up too much processor time.
