I tried one of these (premade) that goes with a pressure washer. I have a 12hp pressure washer but it wasn't able to do much, I think because the muck is full of leaves which jam up the discharge hose (which is a paltry 1.5").
Maybe a DIY one with a bigger hose would work better but I'm not sure of whether a pressure washer is theoretically better or worse. I just happen to have one and not a trash pump.
