I read somewhere that another reason why pigs were considered unclean was that unlike mutton-providing sheep, which you can shear for wool, or beef-providing cows that you can milk, the only thing pigs were good for were pork, and so the Israelites and Arabs forbade keeping them because it was more economical to raise other animals that have multiple uses besides food.
Swine hair could be used to make toothbrushes or any other brushes... but I guess they didn't know this.