I used this stuff before, I don't think it's any good. It does help a little in making you glide across the strings or something, but after a few wipes of it across the strings, the lubricating part of the item gets dirty/clogged with rust and dirt. When that happens technically you're wiping dirt on the strings everytime. I tried wiping my strings with a cloth before applying it, it still gets dirty. I would recommend liquid on cloth kinda lubricants(like the Jim Dunlop one) than this.
Just saying...