I will second that and add a little short story.
I took a coworker to the range one day and he brought his Kahr that had not been shot for something like 1 1/2 - 2 years. His father in law was holding on to it at the time. We could not get 2 rounds in a row to chamber without pushing on the back of the slide. He was ready to get rid of it, so I asked if I could borrow it to see if I could figure it out. The gun had been over oiled what must have been 4-5 times without removing the old residue. Not sure if it was dried oil or grease, but it took me 45 minutes to get the rails clean. After cleaning and applying the correct amount of gun oil (Hoppes if you care), it ran like a new gun. Cleaned it a final time and gave it back to him. Amazing what it does for a firearm to just clean and lubricate regularly.
I have neither the experience or the number of firearms that many of you do, but with 3 rifles and 8 pistols, I can get behind on shooting all of them regularly. Like Iowegan, I pick a day every 6 months to line them all up, clean off any residual dirt, dust or dried oil, and reapply either Hoppes or Balistol. It doesn't take very long to do when half of them have either not been shot or shot sparingly, and it's worth the time and effort to know thy will work when I want them to.
I have bought 4 cleaning kits in my life, regularly shooting for the past 9 years. I have spilled more gun oil than I have put on guns and I still have some in each of those kits.