The "What Is This?" game

[Elmojo]

Not a chimney, but does involve smoke, to a degree. *hint*
Yep, aluminum does corrode quickly, but not from acidic compounds (that I know of). What else corrodes aluminum very quickly?
Not a sabot, but you're still in the right area.

What do I win if no one guesses?! 

[yamahonkawazuki]

proximity fuse?

[Watcher]

Projectile for an Avalauncher?

What do I win if no one guesses?! 

You get a cookie and get to post a new picture.

[Elmojo]

Projectile for an Avalauncher?

I had to look that one up!
Nope, not an avalanche bomb, not a proximity fuse either.

New Hint: It's aerial in nature

[Watcher]

rocket pod, like for a helicopter or something?

[pliskin]

Core sample tool machine tip? Is this guess any better?  ( Google woo rick flair questionnaire).
Weather vein?
Weather balloon air sampler?
Antenna?
I'm sure I'll get it

[Elmojo]

Hahaha no, none of those.
Check my previous hints.
It's aerial, as in, it's made to work in the sky.
Not a rocket pod, but that and the earlier guess of a mortar are about the closest.

[pliskin]

Aerial plane sprayer for spraying stuff

[Watcher]

Is i t a smoke can for a sky-writer?

[Elmojo]

LOL You guys are going the wrong way...although the smoke can guess wasn't too far off...

[pliskin]

OK what wtf is an fracking moon probe with a self disinteresting boring tip that emits smoke when its done

Or maybe its your vaping ecig thing?

[Malfruen]

Is it an old aerial countermeasure dispenser? Like chaff or flares or something? I don't know the technical terms for it.

Chaff chucker? Flare Flinger?

[Elmojo]

You guys are really, really close!
One more round of guesses, and I'm calling it.

[Janx101]

If you say chem trail dispenser by "secret world government". .. I'm going to be really cross!..

Hang on.. .. chem! ..
Cropduster spray tip/nozzle thingy?

[Elmojo]

I have no idea what that is, so nope, not that!

[Janx101]

Nah that can't be it. . Plisky already said that. . Dang!

[Elmojo]

Nope.
So, in the interest of moving on, should we call it a stumper and reveal?

[Janx101]

Pffft why not! .. I'm gonna be annoyed though. . I can tell...

Fireworks launch pod thingermajigger? ... last ditch guess!!

[Elmojo]

That was actually the closest guess yet!

Ok, here it is guys. It's one of these.

For those disinclined to click links, it's a hand launch signal flare. Or more accurately, the spend body of one.
Lots of info I've found online mention them in reference to Vietnam, or even WWII.
However, this one is current issue. I'm not sure if the design has changed over the years, but it sure looks the same.
The corrosion is from the rocket motor and all the nasty stuff it puts off, plus the burning flare material itself.

So, do I get my cookie now?! 
Also, does someone else have something to post, or should I go digging for another mystery item?

[Watcher]

So, do I get my cookie now?! 
Also, does someone else have something to post, or should I go digging for another mystery item?

Cool!

Yeah, I think how we were doing stumpers was you just go again and it counts for 2 points (noone is keeping score, though).  So find something else and toss up a pic already