As a former computer tech, IMO canned air really should be outlawed!
Canned air will do a spit, but that is freon not water. That freon can (and will) freeze something on contact, especially any kind of circuit board.
Given the freezing factor, IMO, using canned air on a bobbin case is a disaster THAT WILL HAPPEN. There is a tempered metal "spring" on the bobbin case. If that spring gets any freon on it, it will loose it's tension capability and most likely break. (That is experience talking there)
I have a longarm and a couple of regular sewing machines. My cleaner of choice is a chenille pipe cleaner. That thing can get in the tightest of places and drag lint out by the truck loads.
For blowing out a machine, there are actually several different options you can use. Purchase a small air compressor like what is used for airbrushing. You can get in very tight places, blow to your hearts content, and not worry about any type of moisture. Some vacuum cleaners can be set up to blow and these do a good job as well. Albeit, you may have to use a lot of elbow grease, in a severe pinch you can use a hand pump. (been there, done that)
For cleaning, I use my pipe cleaners, a shop vac, and artists paint brush. These items seem to work well for my machines.
The last reason I would like to see canned air outlawed, banned and removed from retail shelves is it is much more dangerous than huffing spray paint. About a year ago, a teenager in our community had "huffed" canned air. The freon froze both lungs shut and the young man died before anyone to come to his rescue.
Never put canned air in a hot building (like metal storage shed) or direct sunlight. They can (and will) explode (got the t-shirt for that one!)