I do repair some of my late DH's thick wool Ragg socks. I wear them around the house, and to cover the holes I sewed on a thick padding of felt I got in a yard sale. Then to prevent slipping, I sewed on a layer of rubber stuff you use on Pajama feet. Now that I have a lot of labor and love in them they'll last another 40 plus years. We both wore that type on our back packing honeymoon in 1967. My socks wore out first, for whatever reason I don't know. I love those socks.