Interesting, I’ve never seen this before. How does it compare to regular gooey or liquid flux? Also how does it work? Just bringing a chunk of rosin next to a soldering iron would just vaporize the flux as seen on the video?
When you touch the iron with the rosin, it starts smoking like incense at a church (same stuff actually), but a small amount remains on the tip. You transfer this to the contact you’re soldering, dip into the rosin again, and then solder as usual.