Thanks for the additional information. It is going to be very difficult to stop a situation that has been going on for 7 years. The breed typically lives 12-14 years so he is middle aged. It sounds like this is more of a habit.
I was hoping it was a recent problem as that might point to a tooth issue. When a pup is teething they chew everything and when a dog has mouth pain, they will typically start chewing again. Since he is pretty old, I'd get a dental done to check for tooth issues just to rule that out. Some problems can go undiscovered even with yearly exams. Things that would point toward a mouth issue would be red gums, black raised growths in the mouth, swelling of the gums, broken or discolored teeth.
If the mouth isn't an issue, it is going to take a lot of work to stop this behavior. I'm going to suggest you set him up if at all possible. Attach a leash to him and put an object he enjoys chewing on right in front of him. Then relax and wait for him to make a move. If he goes to chew on it, give a short tug to bring his attention back onto you and a firm NO so he understands it is unacceptable. When he pointedly ignores the object which he should do after a few corrections, then give a high value treat like a sliver of hot dog or raw liver. Once he seems to understand that he is not supposed to put that object in his mouth, get him up and moving and circle him around until he is faced with it again while standing and repeat the exercise until you are sure he isn't going to go after that item again.
Change the objects and start on another favorite chew object that is unacceptable and repeat. Eventually you will work up to having a chair wherever the linoleum and wallboard is and repeat with those areas. It isn't going to be a fast fix but this way you can work with him several times a day for 15-25 minutes each time so the message you are trying to convey has a better chance of being understood. The more often you can train with him, the faster it will go but keep the length pretty short.
The other thing you can do which will help is to prevent the behavior when you are unable to keep a closee eye on him. Crating when you are gone is one way. When you are home, you can leash him to you and thus have him where you can watch him all the time and that will help you stop him when you are not training. Another option would be to purchase a basket muzzle for him. That will allow him to not be contained but for the most part he won't be able to chew on most objects. He still might be able to get a tissue or small cloth and tear but shouldnt' be able to get the wall or flooring as long as no pieces are sticking up.
Sorry for the delay, my client stopped by. As far as toys go, you should have a variety of toys including kongs that you can fill with yogurt and freeze. These tend to keep dogs busy chewing for hours.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.