We kennel trained both of our dogs when they were puppies. When they weren't in the kennel, we kept a close eye on them. I used the leash method, to keep the puppy close by when I was doing things. So we didn't really have issues with chewing.
When they were older than a year, they had more freedom. Cassi started chewing on the baseboards at the top of the stairs when she was almost 2 years old. We retrained her to chew on a bone.
Teka started chewing the exact same spot when she was about a year and a half. It didn't last long. We think that the cats rubbed that spot and the dogs liked it. It happened with the edge of a scrapbook too.
She has been chewing tissues and stuff for at least that long. We replaced all our bathroom trash cans with lidded cans due to her shredding everything. For a while that worked and then she started finding papers and chewing the edges. About a year ago, we figured out that she would chew a napkin and leave everything else alone if we left one out overnight.
Last night, we weren't home for dinner and I forgot to leave a napkin out. This morning, I found a book pulled off the bottom bookshelf and the top bound edge chewed. The two books next to that one on the shelf were also chewed on the top. W. T. F.
So Teka will be kenneled at night. Every night. It's fantastic that she likes her kennel but terrible that she can't be trusted in the house without supervision. On the upside, maybe that is a step to getting another dog. Or not. That's still a huge amount of work, keeping dogs separated, shuffling who is in and who is out. Anyway, I am so disappointed. My seven year old dog is a terrible (but happy) puppy.