Sarah
That thing is awesome. First time I used it was still in Brazil, during those annoying (but necessary) safety trainings at Electrolux.
Some time ago, I remember they used to come in a can that was like a tiny fire extinguisher and it was an aerosol but with that absurd amount (when using it, don't be scrooge)
And yes, it makes a mess because it's a super thin powder, somewhat similar to talcum powder and OMG, that thing causes the worst pain one can imagine for like 10 seconds. Using it you'll definitely scream like the after shave scene on Home Alone. It feels like a mix of burning and being stabbed. (Sorry Kevin, it hurts but it's better than bleeding)
Here in the USA I saw only the two options that came with my kit, one is a large pouch, the other is a tiny tube, for small injuries.
There's no secret, grab the pouch, tear it wide open and flip it straight over the bleeding "throwing" the powder at a certain speed so it won't stay too superficial. The bleeding stops like magic in 1-2 seconds. The powder also has some sort of antiseptic to clean the wound and keep it safe from any infection and it creates a crust to protect, almost like a powder "band-aid".
Of course, this is a first aid, only to buy some time until the victim gets medical attention.
Luckily Kevin's injury was extremely superficial, nothing serious enough to justify calling 911 but you know, even the tiniest cut on the back bleeds like a Frigidaire 1-18 spin rinse. Lesson learned, I'll NEVER transport a Flair (or any other huge stove) again. Better hire insured professionals to do that.
I'm glad I'm a PITA with prevention (the only thing I still don't have at home is an automatic defibrillator, but only because its freaking expensive) when I saw he was injured, I ran and grabbed the first aid kit. 30 seconds later the powder was applied.
Coincidentally, I used the bleed-stop 2 weeks earlier after a dog bite on my face and the same day Darryl bought a replacement box that saved the day. (Next morning I already bought another box to replenish the first aid kit).
One thing I was never able to find here in the USA was that stone-like crystal (looks almost like a small soap bar) or a stick almost like a chalk. In Brazil that's very popular (and inexpensive), extremely useful for shaving cuts, when the manicure cuts a sirloin steak out of the cuticles or when you pop a pimple or blackhead and it keeps bleeding. I have no idea how that thing is called in English, a direct translation risking a false cognate would be "hume stone" and it's as useful as bleed stop powder, it's reusable and it doesn't make the powdery mess.