I did this also - forgot about that.Inserted cartridge, pressed down, placed second cartridge above cage.
Prolly did more damage to the contacts in the system, but it worked like a charm.
My friends dad used a big qtip looking thing with a alcohol type solution and it really helped some problem games.
So basically what you're saying is, "a Nintendo cartridge is like a toilet, when it doesn't work, all you have to do is jiggle the handle"!