The bin on mine drops from below onto its casters, it has a screen that allows the fluid to drop and a valve to drop this out of the bin. A bin bag is placed over the bin and the bin is tipped to put the debris into the bag. The grief is that the screen is welded and fines get through - I pressure wash the bin regularly. I can see benefits of having a gorilla bucket with holes but the real grief I find is clearing gutters when its raining, thats why the drain valve is a god send but a pump out ..........................