I don't use it much
I had a couple issues with this one. Firstly, it only cleans the tops of the strings, so the bottoms will still be grimey anyway. But aside from that, while it does clean them it also leaves them... well, slick and greasy. I just didn't like the feel and found myself not wanting to use it for that reason. That's probably a matter of preference though, some may like the slick feel.
Only cleans the tops of the strings