There is many myths about this stuff, I was not afraid to test it in the bright new tip of my AT90DH station.
In a way it removed some burned particles of solder cream, and the tip it does look better in a way.
The cleaning helped the tip to gain a bit more usable area which now can store some more solder than before.
I will need some time to evaluate this properly, but yes it does help.
The texture of it is not creamy, feels more like a solid area which you can rub the tip on it, under high temperature there a bit of smoke and melted solder comes in the surface of it.
So far I like it.