Here’s a quick one that you have to click through to view in detail.  Thanks to Stuart VK2FSTU for the link.  Solomon NH7ZE says:

Here is an old ham radio operators trick for cleaning wires for soldering that are old and corroded.  It is hard to find this technique printed anywhere!  I am a ham, NH7ZE, and learned it from my elmer (mentor).  I am passing it on.  I hope it helps people who need to clean wires  😛

See the full article by clicking here (or the picture above), as hosted on instructables.com.