I use canned air often to blow out the lint. I have seen pictures of list throughout the inside of a machine. However, when I spoke to my repair tech, he said it is okay to use canned air, but to only blow from back to front. My machine has a small door (with the bobbin mechanism inside) which drops parallel to the table and the lint escapes coming forward from this area.
Since machines are expensive and becoming more so, I think it is imperative to have them serviced atleast once a year. This way any accumulated lint throughout the machine is removed. This is particularly true if you stitch a lot (which I do).