Both wood chips and calci sand have proven to be dangerous for dragons. Wood chips have sharp ends that if swollowed can cause internal damage, not to mention impaction. Also, being alot harder to spot clean, the woodchips can harbour bacteria that could be bad for your dragon's health (not so bad if you clean all the woodchips out every week). Calci sand is not digestable no matter how much the petstore or company claims. It tends to clump as well, which can cause severe impaction when swollowed.
I am not convinced with the safety of wheatbran that alot of other posters here use. To me, it is no better than calci sand as it clumps and tends to turn hard and crusty when being soiled by dragon droppings. Also, being a food item, it can spoil if not cleaned regularly. I have also heard of it clumping and drying around the vent, causing irritation to the dragon. So I don't personally recommend it but between calci sand and bran, if I had to chose between the two, I would choose bran.
Washed Playsand has been used for adult dragons alot and for the most part, is not harmful to the dragons. Most dragon owners who use washed playsand, don't feed their dragons on it. They feed insects in another tank or lay down a sheet underneath the food, this way keeping sand injesting to a minimum.
Though I haven't used the non slip self liner (can't find any wide enough so I don't have to have two pieces in my cage), I do use plastic tablecloths. It has a slight texture which doesn't hinder my dragons' ability to run across it. It is very easy to spot clean (just pick up the poo, wash the spot with a mild antibacteria soap, wipe up the soak and dry off the spot). I change it once every month though, to ensure no germs accuminate underneath it as it does tear easily.
I deffinitely recommend either the shelf liner or plastic table cloth for dragons cages. Both are relatively cheap (I paid under $20 for a roll that is 3' wide x 100' long), easy to clean and manage (no lifting 50lbs bags of sand around the house), don't cause allergic reactions (like rabbit pellets or dust), are not dusty, can't be injested and are aesthetically pleasing (both self liner and tablecloths come in a variety of colours and patterns).