When blood becomes a "set" stain in a garment or fabric, removing it can be difficult. MCC supply salesperson John Sullivan has a couple of processes that he has found sucessful. If the garment is white, an application of 35% hydrogen peroxide followed by recleaning or laundering often works well.
If the stained item is of color, using So Go 1 from A.L.Wilson is usually successful. So Go 1 can be applied as a soak solution or by direct paste application. After any application, the item will then need to be recleaned or laundered. For more information about A.L.Wilson's SO GO 1 go to http://www.alwilson.com/secondary/sogo1.html