Tried boiling bass guitar strings once. Brightened 'em right up. For about a day. Phooey.If you're totally broke, and you have to try it rather than just replacing th' durned things, try the following:
Get a pot that will never again be used for food prep and fill with water. Add a goodly dose of vinegar. You want to boil the strings for about half an hour.
Don't know how long the treatment will last; I didn't have the "recipe" when I tried it.
Lord, how I HATE restringing instruments! Sorry, I had to get that out.