وَشَعْرُ الْمَيْتَةِ وَعَظْمُهَا طَاهِرٌ
Translation: The hair and bones of a dead animal are pure.
This ruling is separate from the tanning of carrion hide. Tanning is the issue for the hide, while hair and bone are treated under a different juristic rationale.
The general principle is subject to the stated exception concerning pigs and to distinctions such as cut hair versus hair pulled from its roots.