Birch bedding? Teabag bedding?

[PetsareGreat]

Hi everyone

I'm getting ready to bring home a hamster.
Am currently trying to find a substrate, and came across Rodipet Birch bedding.
Was wondering if anyone else is using it / has used it and what you think?

Another one I found is teabag bedding, again, anyone using/used it and what do you think?

For both of them are they good at keeping up tunnels?

Thank you.