You know the trick. When the game wouldn't load properly, you would take it out, blow in the open end to dislodge dust, grit, peanut butter, or what-have-you from the electrical contacts, then put it back in and hope that it worked (or repeated as necessary).
I personally used the T-shirt variation whereby you stretch the front of your shirt over the open end of the cartridge, then blow through it—the shirt captures the dust and prevents you from spitting into the game as you blow.
Thing is, I still do it. Like, regularly. Any time my gadgets act up—boom, I've got the battery out and am blowing like a Nor'Easter into my electronics. Anybody else still do this too?