I thought about White Phosphorus. If that’s what it was those guys were even tougher than we thought. I would be really leery of a bit of the stuff ‘splashing’ back onto the shooter upon release. Not something I would want on my pink & tender skin. The other reason I wonder about White Phosphorus is if I’m not mistaken, they shoot a hat with a smoke arrow. Seems as if it was the White Phosphorus the hat would have caught on fire.
In one of the scenes, they appear to dip the end of an arrow into a bucket before shooting. Possibly something like liquid Nitrogen ???
Still an awesome video. Now I need to watch it again, just because.