How much time do you have to do coop cleaning? Are you willing to scoop poop each day in lieu of doing a full cleanout weekly/monthly, or is that out of the question?
If you're willing to sift daily, I'd recommend chopped hemp. It sifts well since it's finer than shavings and seems to be pretty absorbent. I've been using it a few months so far, under my roosts, and have seen no need to do a full clean it out at all so I plan on just adding more material as needed.
Alternatively, you could skip the daily clean ups and go for full cleanouts whenever the poop load gets to be too much, but the frequency for that varies wildly based on how much space you have, number of birds, ventilation, bedding used, etc. In a small coop, you could be looking at weekly or monthly cleanouts.