Bitter sprays and harder toys don’t really solve the problem, they just sort of… prevent your dog from using chewing as an outlet.
Your dog might be bored, because he’s a puppy and a labrador. Try giving him a job to do, or giving him something more enriching to do (check out the Canine Enrichment page on Facebook).
You should still allow him to chew things, imo. Just give him appropriate things he’s allowed to chew, and when you see him going for your furniture or shoes, give him his own toy or nylabone or stick. He should catch on pretty quickly!
Good luck anon -C