i would try this
NaturVet Bitter Yuck! No Chew Spray for Dogs, Cats & Horses at PETCO
i had a problem with my furbaby Polo chewing on the walls then i started to take him on a longer walk 45 minutes plus 15 minutes training inside and 10 minutes training outside and i put unscented deodorant on the the corner of the walls and he has not touched them since and i give him lots of bully sticks