We had a lab that would eat remotes, cell phones, and pretty much anything that was left around.
We did a couple of things to get him to stop. Every time, as soon as we got home, we would find a toy (tennis ball, rope, whatever). This associated us coming home with toys. In order for us to play, he needed to find a toy. Now we can say "where's the ball" or "get your rope" and he knows exactly which toy to get. Leaving for 10 minutes, then 15, then half an hour, then an hour helped work his "tolerance" up. Within a few weeks, he stopped chewing up things. He was about 8 or 9 months old when this happened.
Our other yellow lab wouldn't stop. She would eat remotes, shoes, and even pulled a couple dozen books off the shelf and tore them up. We finally had to get a crate and put her in it when we left. After a couple years we tried it again, and she has stopped eating things, so both dogs are left out when we leave.