I seen this documentary ages ago
He explain's it in the video.
the first time they beated the thc/resin from the plants they called it first sieving quality, super,
then they beated it for the second time they called it 2nd rate quality
and then they done the same again for the third time and called it 3rd rate quality,Zero
now remember they took practicly all the stuff from them the first and second beating they gave the plants,
then they thin 3rd rate quality down again for business

and you get soap bar
and you get more powderd leaf material than any thc/resin in the soap bar
and yes that is bars of shite bar he has in the video saying it will blow your brain.