Over the years I've purchased a few different type of guitar string cleaners. Sprays, special cloths, even a lubricant that not only cleans your strings but lubes them up for faster playing (lube? Did he just say "lube"? ). Yes...it's pretty slick stuff. :). I found that most of these products did what they claimed - they took the dirt off my strings. Recently, however, I came across a cool invention that doesn't use any type of liquid cleaner to get the dirt off of guitar strings. It's called "The String Cleaner". It's a device that you put around your strings and run it back and forth the neck a few times. The material that cleans the strings is a microfiber pad that digs out the dirt and grease that get caught in the strings. The pad is reusable and cleans up with soap and water.
The benefits of cleaning your guitar strings is that it increases their lifespan which can save you money in the long run because you wont need to change them as often. Now with that said, some people prefer the sound of a fresh pair of strings and don't mind frequently changing them. I try and change my strings every couple months. "The String Cleaner" does come in handy when I get lazy and leave the strings on longer. It doesn't take long for the strings to start getting dirty so I recommend some sort of guitar string cleaner. What kind do you use?