Similar experience here. I was at a party the evening before a flight and had loads of rockets and small mortars stuffed in my cargo shorts, which we were running around and shooting at each other (alcohol may have been involved).
Next morning at the airport was my first time seeing these machines. As the machines doors opened and closed, jets of air puffing at the passengers ahead of me, I wondered about the shorts which I still had on. I looked down at the empty pockets and they were literally sparkling with gunpowder and other residue from the fireworks the night before. 'Let's see what happens' was my only thought and I felt a bit let down when I got through with no problem.
Edit: Shorts sparkling in the light with some kind of crystalline residue from the fireworks, not sparkling like a lit sparkler, which would have been even more impressive.