On wood shavings sold in Czech republic there is no information from which kind of tree they are. So I can't choose. But I heard from people who live in another parts of the world, that pine shavings are good and that cedar shavings are not good. I use only shavings and I add some hay but it's more food than bedding and degus eat it all. I give them also couple napkins each time to sleep on. They sometimes use them and sometimes sleep up on branches.
Some degu breeders use bedding made from corn which is sold here mixed with shavings and straw. Every breeder uses different bedding - what seems to him to absorb most. And what is not harmful to degus of course - like a lot of dust in shavings or some chemicals in shavings.
I was also asked, if sand would be good for bedding. I don't think so, nobody I know uses it. And if I leave the dust bowl (which degus use for bathing) in their cage, they use it as a toilet and after a few days it smells bed, so it seems that sand doesn't absorb any odour.