well the sparklite is just a small ferrosium ( or however you spell it) rod, mounted on a spring, against a abbrasive wheel in a plastic package.

just like any ferrosium rods, they are sensitive to moist. The sparklite has the advantage of heaving plastic around the rod, but because the rod is also a lot thinner than, normal rods. It will corode the intire rod a lot quicker.

Scraping a new ferrosium rod, will remove the black protective outside. Which will make it easier to corrode. But this doesn't mean i can't corride, when its new and unused.