What do you need something to chew for? Just asking because if he's older he probably doesn't need to chew.
If it's to keep him occupied, you can stuff a Kong. For a low calorie stuffer I use cooked frozen veggie mixed into a mashed boiled egg, or stuff with some mash potato or pumpkin.
If it's about his teeth, you'll want something that takes a few chews. I give mine a small piece of lean meat, like pork steak or sandwich steak (cooked), just enough that they have to chew it, so generally between the two of mine I cut up one piece of small steak into four pieces and give them two pieces each, they have this twice a week. You could probably also give a boiled chicken breast to chew on. Does he like fruit? Deska will chew on pieces of apple, he won't eat raw carrot, but if your dog does that's an option - to give it as a whole carrot. Otherwise include big chunks of cooked vegetables in his dinner - big enough and firm enough so he has to chew the pieces. Otherwise you may just need to brush or add something to his water.