While at the LQS where I purchased my machine, I inquired about using the canned air to blow out my machine. This is what I learned. Most of us, including me, blow into the machine from the front. This is incorrect. We are to blow from the rear, have the bobbin casing area open and allow the lint to blow out the front door. This means standing behind the machine to blow. It all makes sense to me now.
Just thought you'd all like to hear another opinion.