I love deep litter. I found I had to add some shavings until I got the magic depth that was not stinky. Throw in some scratch or whole grains every day and they will keep it well-turned. Proper depth and constant turning, along with not over-crowding, seem to be the keys.
You can help them under the roosts by loosening the crust with a spading fork on occasion to get the mixing going.
Don't use moldy hay for bedding, mold is bad for everyone, including chickens. The other thing that might produce bad dust is if they spill their water often, the bedding might mold or get stinky. So re-arrange your watering system so it doesn't get tipped over if this happens more than a couple of times.
This fall, the maple leaves fell during very dry weather, no mold, so I filled the coop and the goat stall with them....very nice. They will break down and make fantastic compost. I will add shavings as needed to supplement the bedding as they break down, but I haven't needed to yet. The chickies are already shredding them...very exciting to a gardener!