Interesting- I just happened to be in the bernina shop talking to my machine maintance man while he was cleaning a machine and he was using canned air. This is a very reputable bernina dealer and has been opened for 30 years. I wonder if there's a certain way you should use it? The one thing I noticed is that I didn't see him do anything for the $70 fee that I don't think I could do at home myself. But, out of the fear that I'm missed something really important that he was doing, I keep taking it there.