I've run glass beads in my cabinet without losing them to the filter.
These are fine enough to be like powder to the touch. I think that
their density is too high to remain air borne long enough to be sucked out.

"Sand", on the other hand probably has much more dust that would be
lost, but that's no loss, if you know what I mean.

When I built my cabinet, I used a vac to clear the air inside. Using a
blower puts positive pressure in the cabinet, which would exploit the
tiniest crack to drive dust into the shop. Is this the way that it's
usually done?

Bob