Tagging onto this post to say that this is a legit solution.
I was having to mash the ever-loving crap out of the B button & Start button on my PocketAdventures board to get them to register. Cracked open my GBZ and reflowed some solder onto the button pads, and all's well. Definitely use your isopropyl alcohol to clean off any residual flux before reassembling, or you're gonna have a bad day.