Crush your ice up some before doing your run. Sharp little pieces make better "exfoliants." Use a sprayer full of icewater to rinse your yield against the mesh once you've drawn up and drained each bag. This will help any residual plant particulate fall through, ensuring a clean yield. Do this over the bucket, so that the spray water drips into the next bag. The yield should lighten from green to gold.
“For the sake of future generations, we MUST collect and study wild and weedy relatives of our cultivated plants as well as the domesticated races. These sources of germplasm have been dangerously neglected in the past, but the future may not be so tolerant. In the plant breeding programs of tomorrow we cannot afford to ignore any source of useable genes.”
- J R Harlan