How do you clean the ignition switch / barrel

[carrier]

Use electrical contact cleaner.  Squirt a load down the key hole, stick the key in and turn it on/off a few times.

I had problems starting (turned over fine but no spark) which turned out to be a dirty ignition barrel, this fixed it.

I've been having this problem for a while now...where have you been!?!?! I think someone needs to make a common problem post.