minus the lead free its the same stuff they sell at radio shack
honestly there is only so much flux + solder flakes + vasoline you can come up with
not saying its bad, but it hardly does anything aside from burn off oxidization from your tip (which you should not have as tips are inexpensive even for the most expensive stations, and I love the "pros" who have a clean tip but 8mm thick of crystallized crap behind it)
and for the record, I use the maroon 3M abrasive nylon pads, those are mid grade abrasive (standard green are slightly heavier) and you really have to muscle down to scratch metal with them, though crappy melted plastic goo is no match (and they blast though water clear led's for frosting)
obviously don't use much if any heat with a polymer product
this tip is nearly 1.5 years old with hours per day, nearly every day use with nothing else but proper tinning, a brass sponge, and the occasional wipedown with a (mild) abrasive nylon pad
and yea, I have got plastic all over it on more than one occasion, in fact 3 days ago while meddling with a xbox analog stick, I started bumping it into the casing enough were it started to stank rank