The only thing I use to clean my machine is a long pipe cleaner. It picks up the tiniest amount of lint. I've been complimented by my mechanic several time for how clean my machines are. Last time he was here he said my machines were the cleanest he's ever seen. Hence I only need to have them serviced every two years. I do clean them regularly but not at every bobbin change. He also said to give canned air a big miss.
This guy was head mechanic for Janome for 15 years here in Brisbane.