We have been bleeding our fish for years. Once you decide to keep the fish, put it on a stringer, hold it over the side, and cut its throat with kitchen scissors( much safer than sharp filet knives on a rough day). Then throw the fish overboard for 5-10 minutes for it to bleed out. At that point you have to put the fish in a cooler, but the filets are extremely clean at the filet table, no blood. We also cut the dark meat off of the filets after we clean them. It helps if the filets are cold and firm so sometimes we do it the day after the fish have been cleaned and sit in the fridge overnight. We will lay the fillet flat with the dark side up and gently shave off the dark stuff with a sharp rapala knife. We also zipper the fish, essentially removing the dark / bony section that runs through the centerline of the filet.