Nooooo, it's clean! And not that kind of timer.
There were just some traces of black powder in the galleries when I found it (on a wreck), which I cleaned out with a stiff wire brush by the light of a naked flame.
The wreck (SS Volnay) was carrying hundreds of boxes of these little beauties when she sank in a gale. Loads of small lead shrapnel balls all over the seabed too, which is how you find the buried boxes...
I couldn't find the main shell case that went with it, now that would have been full of 'spaghetti' cordite. Still, wire brush and a naked flame for that too...
The old saying: 'Come on now, bite the horsecock'. Not forgetting the pride of Japanese railways 'The HorseCock Train'.