how to use water soluble flux?

Hey, so i got a little Water Soluble Flux with my Soldering Gun (new to this) 

Well it turns out that this stuff came with no instructions and I cant seem to find out how to correctly apply it.  this is what I bought


Someone please help?

The right type of solder for electronics work contains flux inside tiny tubes in the wire. This looks like solid solder + separate flux - not a good idea for electronic work.

If you aren't using it for electronics, then you smear a THIN layer of the flux on the two halves of the joint, heat and flow in the solder.