Great, there is a couple urine spots so I'm wondering if I should just treat those with acid and flash them? And then maybe I'll just top down clean the face and backing? The urine could be trapped in the backing which could cause issues if I wash it in the pit.
If you do soak it be careful about moving it/agitating it while wet. The backing is glued on and you could accidentally damage the glue leading to a big mess and a damaged rug. In my experience the backing will be 100% cotton but that shouldn't be a big issue if you can dry it fast and, as stated, face down.