Never tried stuff like this before. But I bought it and was very surprised, because this bottle can repair your not very old (not older than 6 month) strings! If you clean the strings after each time you play, you can literally play on fresh strings any time. Will buy one more when my bottle is finished.
ProsReally clean the strings.
I am using this stuff for a year now and there is some fluid left in the bottle anyway (~25%)
ConsCloth of the applicator fell off since some time (6 month). Since then, I am using this stuff like this: put some fluid on a cloth and wipe-off the strings.