Now this is probably an Australian colloquialism, but <avert your ears delicate readers> bulldust is another way of saying bullshit, what a load of rot or what a heap of crap.
So with this knowledge in hand, imagine my surprise when I found someone has actually bagged up Santa’s dust and will happily sell it to you to enhance your Christmas experience. It has sparkles in it. What has that poor man been eating? No wonder his cheeks are red.
Of course, it could instead be a bag of cremated Santa. “Um, kids? Christmas is cancelled due to a death in the family. Bad luck eh?”
Talking of dead Santa (yes, we were), Look Mama! has a card about just that. Inappropriately happy coincidence…