Flux in flux cored solder is rosin, rosin is distilled from pine sap and is a permitted food additive. It’s as a glaze on chewing gum and pharmaceuticals.

Rosin is also used on violin bows to increase friction, and it’s the white powder you’ll see gymnasts and baseball pitchers apply to their hands to improve grip.

Rosin vapour is a lung irritant, so avoid breathing it by using a fume extractor, and for some people it can cause contact dermatitis.

Yes it’s horribly sticky, that’s the worst part about it really. Isopropyl alcohol will dissolve it.

Electronics is not for you

You don't have to touch it or eat it ;)

Hog lard also works. Do you hate bacon, too?