Flux helps break the surface tension between solder blob and wire so I really doubt the flux in the unmelted solder would have a path to flow to the wire. But

Flux helps break the surface tension between solder blob and wire so I really doubt the flux in the unmelted solder would have a path to flow to the wire. But yeah, my solution is to just dip the wire in a jar of flux as I’m stripping and twisting them