DIY Fluxes with ethanol-propanol-x-nol
Why have non-rosin core wire? Solder paste is flux with solder granules suspended in it.

You can use it on the surfaces beforehand or a drop on desoldering braid. Keeps things flowing :)  Also, SMT.

I've usually seen propanol used as a solvent with resin. As little as possible to keep the active ingredient usably thin.