If it’s soaked in blood, you may need to spray it down with a power sprayer. Use a pressure washer to hose it off in the driveway. Then soak it in a tub of ice-cold water for about 30 minutes. Then hand or brush wash it, and then dump out the water and repeat with soapy water.
If you can, use a detergent made specifically for cleaning hunting gear. Give it a good rinse, and then hang it to dry.