Believe nothing you hear and half of what you see.
Let's see that catch can. BTW love the color.
I just pulled out a bunch of sand from a pair of used valve covers (champion,GN1) style with breathers. I got lucky because I wanted to clean them out in case the previous owner had particles in his oil... So I sprayed brake cleaner up inside the flat part and dislodged a few big chunks of sand.
The Chinese dude didnt get all the sand out and im thinking it is plausible in your case.
Note: this is just one. I found several, but crushed them in my hand to see WTH it was. Sand for sure!
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