I use hemp fiber as a filter in my miniVAP Flexicone modules (wire basket and silicone lid).
It keeps all those tiny tiny dry herb particles from being sucked upstream into your mouthpiece (or mouth).
It also keeps this tiny herbage out of your hydratube or bubbler. The water and glass walls no longer have tiny particles, just golden goodness. I'd say hydratube goes 5x to 10X as long between cleanings with the filter
I now use a much thinner disk of hemp fiber so it is not so restrictive.
Pic is of use in my herbalizer.
When gunked up, vape the hemp fiber of course.