Good question....any answers out there for me and kuntrygirl?
Keeping them off the ground , for a day does help...no mud, dirt, withhold feed off the ground , no grass or garvel in the crop, only reason is that much less to clean out , when you clean them.
Yes many people don't, but if they want to wash the grain and poop out , more power to them, myself the less the better, large animals like hogs and cattle , heck of alot better.
That advise about keeping them off the ground for 2 weeks and feeding only corn does sound like advise better intended for those raising meat birds for the market. I would find that to be more trouble than it's worth for the birds I butcher for the family table.