One of the suggestions for revitalizing a dead home button on an iPhone 4 is to use rubbing alcohol. Turn off your iPhone, put a few drops on the button, and press the button rapidly to let the alcohol go in and get rid of gunk and stuff.
For me this usually works fine, but within a few days my home button problems start coming back.
But if the problem is that the iPhone home button degrades over time, why does my button go through periods of unresponsiveness, followed by a week of “OH I LOVE MY PHONE AGAIN! IT’S WORKING THE WAY IT’S SUPPOSED TO!”?
My brother, who repairs electronics equipment from time-to-time, recommends a different approach. Don’t use rubbing alcohol. Rubbing alcohol will dry out the contacts of the home button and something something. I stopped paying attention. He said to try some De-Ox-Id. It has a lubricant and blah blah blah I stopped paying attention.
I tried it and now my home button seems to have a firm click feeling. But that could be from the part of my brain that tells me Safari gets faster with every point release.
Maybe De-Ox-Id is a bad idea too, but if your home button is screwed and your last resort is upgrading to a brand new phone, it may not be such a bad thing to try.