Question about creating and using inflammables as weapons

Let’s say you use Alchemist to create some kind of inflammables as weapon. Then,

i. One use counts for an action or lasts for the conflict?

ii. How do you pack them? Pack one per use, or per uses made in a single test?

iii. To use an inflammable weapon in a conflict, do you have to have it in a proper slot (belt/weapon(?) or hand) before the conflict starts?

i) I really feel one use only but with a lot of punch is the more entertaining option. Against the right opponents, it should be devastating; I’m thinking both mummies or similar creatures weak to fire AND animals or other beasts which are very afraid of it.
ii) Feels like they could stack like lamp oil does, they ought to be of a similar size?
iii) I’d allow anything but backpack to use right away. I’d also let a character retrieve it during combat provided she spends a round (NOT helping, but doesn’t need to be the acting character) and describes rummaging through her pack, and also does NOT suffer any disposition loss. NOthing really RAW about that, but it’s how I’ve run similar situations (retrieving a scroll mid-combat in this case).

As you see it, it should work the same way holy water works: one use per action, and Pack 1 per two uses. Fair enough.

Storapan’s got it. The multiple use factors are there for creating large batches. Each vial would be single use, but you’d get multiple vials worth of incendiary.

I have come to the conclusion that the Weapon Effect factors are probably overkill. I think I would probably eliminate that set of factors and just have incendiaries provide +1s to any action.