The horses at my barn when they chew on the wood they get a no, well multiple no's. when that doesn't work we put Tabasco or lemon juice on the wood. lemon juice first, some horses like the taste and continue haha. bayley had a jumping issue on the side of our house. ran straight to the flower beds and leaps into the window, like a confused bird. As if she thinks its a hole she can leap through into the house. well after like 2 weeks of sounding like somebody trying to break in, she started just jumping up and putting her paws on the window and chewing on the little ledge surrounding the windows. I tried the dog stuff to keep them from chewing (the apple stuff). Didn't work, she was still jumping and minor chewing. After that, and convincing my mom that the Tabasco would work I just put Tabasco on it. She jumped up got a whiff and hasn't been up since. keep in mind this is after we chicken wired the entire bed, 4 feet tall and she was jumping it. we put hot wire and she just ran through it. shes just a weirdo
you can try it if you want. some people might disagree but it works. if it didn't the first time i wouldn't continue. we let her smell it when we put it on and a few hours later she tested it out when we were inside and like i said got a whiff and was done.
obviously try the kong toys and stuff first, maybe he just sees how nice the deck looks and wants a little destructive attention
good luck