I have tried lots of different stuff over the years and like using this on my sub adults and adult dragons.
http://www.petco.com/Shop/Product.as...sultRedirect=1
Unlike alphalpa, it doesnt have that smell, it is very absorbant and cannot cause impaction, it falls apart when in gets wet. I dont give my dragons water on this bedding because if it gets wet for a while it can mold. Great for spot cleaning though.
I also have outside enclosures with carpet on screen bottoms and that where they soaked and hydrated.