I don't try to 'clean' the run, instead add dry organic materials of varying sizes, shapes and content(dry leaves, ramial woodchips, straw, twigs, dry grass clippings, etc)
to help break down the feces and replace the volume of 'soil' that amazingly seems to 'disappear' after the first year....
.....they like to dig huge holes and fling the dirt and the soil will also compact.
It really helps keep the odor down during rain/snowmelt.
Get the organic layer deep enough and it will help 'absorb' the water runoff and provide habitat for micro and macro organisms that break down fecal matter.....
...and that chooks like to eat.