Why not wood shavings? They don't need soaking like the pellets, so your bedding stays dry. I would have thought that with artificial turf you will get a build up of droppings under the perches as there's no loose bedding to cover them. With hosing down once a week, not only are you making yourself extra work now that the days are shorter, but you will also have the same problem of it not drying out. The dry shavings will be moved about over the droppings by the poultry and will keep their feet a lot cleaner. You can also just add a few more shavings each week to keep the floor clean, and have a deep litter system over winter, which again saves time.