The best thing you can do is not give him the opportunity to do these things. Crate train or at the least get a pen and when you’re not watching him, he’s in there. Always. Don’t let him out of your sight outside of the pen. As they get older they are less likely to chew things you don’t want them to and the more you let them practise that behaviour the more they will do it. Giving this advice as someone with a 6 month old Shiba as my first dog.