For my 2¢ worth, I started with about 12"-14" of pine shavings and hay in my coop. That was over a year ago. I've added about a square bale of hay since. I have a small rake I use to turn over the surface. In all that time, I've only needed to rake it maybe 10 times. I've never removed any of the hay or shavings. The odor is very minimal. I have 8 chickens that free range during the day and only coop up at night, or when they are laying. My coop is about 5x8. I'm not sure this is what is referred to as the deep litter method, maybe so. But I can tell you it works GREAT!
Now, outside the coop, in the pen, I started with hay, about 18" deep or so. I've added hay 4 times. It drains well, is low maintenance, and again, odor is minimal. On a few occasions I need to keep my hens fastened up in the pen. They never scratch to bare dirt. The pen isn't mucky at all. I don't have to rake it because the hens keep it scratched around.