That's fine, and no, it isn't just for plumbers. The stuff is AMAZING when used on RC solder joints as well. I even use it when I want to UN-solder something. It literally reduces the amount of time it takes for the solder to melt from 1 second, to almost instantly. Anything that reduces the amount of heat that makes it into the electronics, the better.

The only downside to using Flux, is that it requires a tiny bit of a wipe down when finished as it leaves a sticky residue on the wires when done.

"The role of a flux in joining processes is typically dual: dissolving of the oxides on the metal surface, which facilitates wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing its oxidation. In some applications molten flux also serves as a heat transfer medium, facilitating heating of the joint by the soldering tool or molten solder."