The Kong Toys that you hide treats in are wonderful. Largish balls that will move when bumped. Toys with noisy squeakers inside.

Couple of ideas that have been good for us with teething puppies (although 4-5 months is very normal to be destructive and also challenge instruction – highly recommend spraying with water for reprimand as needed)
– soak rope toy in broth and freeze
– lick mat
– calf shin bones
There are also a lot of technology advancements like the two way talk camera that is in a competition on this site at the moment or automated ball throwers. Does he have a friend?

we are in the same situation. I get the kids to play with him and wear him out for a good.30-45Mins. I have treats i freeze and lay around, he has a kong full of different things and paste ajd another with bikkie treats. We have like a kong treat ball which i put bikkies in and throw a pigs ear out on the grass. The vet told us to get like a tyre and hang it from a tree for them to tugg at, anything to keep them “heavy lifting”.

I think with dogs, they’ll always have some kind of boredom no matter what toy you leave them. The toys become somewhat like furniture that they just get over fairly quickly. I would suggest trying to take out a lot of their energy with long walks before you leave for work so they can rest most of the day. Otherwise have you considered a second dog to keep each other company?

No matter what you put out for your 6 month old puppy, he’ll still destroy things. He’s a baby and not liking being alone. One thing you haven’t listed is lucky mats, many dogs are comforted by these