I have a bit of a theory -
After lots of huskies, and lots of years of crappy filters and fines sneaking in I've started running mesh filters with oil.
I now see no fines in the intake. I reckon that lots of the smaller huskies don't seal that well around the filter and with a flocked filter they start to suck around the filter instead of through it. Greasing the filter edge helps, but oiling a mesh filter gives the best results.
All just my results, in my conditions, but I'm 99% convinced I'm onto something.