inhale it, people do it all the time

Push her in the dirt then say you're sorry and dust her off... It works for the Sour Patch Kids in commercials.

How the hell would I hide it? The thing is pretty big
How the hell do you casually whip out a can of dust off?

Wear briefs that day, and put 2 in there. As she's falling in to the dirt pull that one out and the other one will just look like you have a huge dick. Also, say you're a computer engineer. Smart is the new sexy.

But.. they get cold. Really cold

Just don't shake it or spray when it is in your pants and you'll be ok.

If both start off in my pants, won't she notice the huge bulge to begin with? The thing is as tall as my outstretched hand and kinda wide. And then if I whip one out, won't she assume the other was one too? (or that my dick magically halved in size)?

No, you see you push her from behind that way she doesn't see you until you help her up.

Shes bound to notice my dust off girth immediately
Shes gonna notice it halve in size. She'll call me a phony and vomit in my shoes, just the like all the rest of them.
This is hopeless. If dust off can't get me laid, nothing will.