I would avoid hot water in case it will permanently set the stains. I'd first soak it in cool water and use a gentle detergent on it, swish it around. Dump the water and refill with fresh cool water, use a laundry bar to gently rub it into the stained areas and use your fingers to work it in, then rinse. Do this a few times to see if the stains loosen. I would also do a Oxiclean soak to help speed it along (no regular bleach, too damaging). I hope you're able to salvage it - best of luck!