I asked Jabir bin ʿAbdallah about riding on the sacrificial camels. He said I heard The Messenger of Allah (SWAS) saying ride on them gently when you have nothing else till you find a mount. (Using translation from Abū Dāʾūd 1761)
سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ ارْكَبْهَا بِالْمَعْرُوفِ إِذَا أُلْجِئْتَ إِلَيْهَا حَتَّى تَجِدَ ظَهْرًا