Some "kittens" never outgrown this, btw. I did the hide away cords thing, initially. But, my chewers moved on to bigger and better things. I have a shower liner that looks like a cheese grater, bite marks on the corner of my computer screen, wooden shelves, books, wires, you name it. I have two nice cat figurines with chewed off ears. I did find the aluminum foil works great, and is cheapest.

I have cats that are possibly a million more times more destructive than a 12 week old puppy. :-0