If you use canned air, and you blow lint further up into the machine, think about this....inside the machine there are parts that require grease and oil, metal on metal moving parts...right? Well, some oil or grease is bound to get on the lint inside the machine, which makes it very sticky. What will stick to oily lint better than anything else? More lint! Soon you have a packed house and a malfunctioning machine. I have a friend who used canned air in her machine regularly, and now in order for the machine to work, she has to hold a blow dryer on it, on hot, for about 5 minutes before it will start. Reason? Probably a piece of greasy lint caught in the circuit board...somehow, the heat is expanding something so that it will work, may not have anything to do with lint, but why take a chance? The canned air on mechanical machines is probably not as much a thread as on computerized machines, due to complicated circuit boards, mother boards, etc. This is why it is okay to use it on sergers, they are mechanical, you can see the entire works when you open the front... but I don't use it on my serger either, I just have too much money invested in my machines to take a chance like that.