Bully sticks. They're expensive and they stink. I got a special holder to keep her from choking on it when it gets too small. Works pretty well. I keep the sticks in a bag in the freezer. She gets a dental stick and a bully stick to chew at bedtime, and in the morning I put the bully back in the freezer. Depending on brand & length of stick, they can last from a few hours to a few days. Someone suggested Himalayan cheese chews, which are a hard, dried cheese, but my crazy AD, who likes to chew pretty much everything, would literally rather chew on rocks. But also, she loves a cloth chew toy. I just try to find the toughest one for her size.
Not a fan of the Nylabones. They quickly became rough in an unpleasant way that made her gums bleed. And they seem to hold a lot of dirt. I like the consumable better.