The cattery idea is very good. Alternatively if you have a garden a small outdoor shed with a window would be a good idea. Your kitten could stay in there when you are at work with a bed and a tray and some toys. He would then get used to the tray and playing with toys rather than destroying things at home. Give him a shelf near the window and adequate ventilation in summer. I have an indoor and outside run on a shed for my Persian and he oves being in there.