I use a pitch fork once a week and rotate the bark shavings "Fluff and Flip". It keeps the droppings from accumulating on the surface, no smell, well ventilated and dry. We have 36 ladies and we are all happy!
The outside run has about 4 inches of hay which gets turned as well
I will change out 3/4 of the coop shavings to the compost pile and replace it to 12inches for 6 more months