I also thaw mine in a cup of tank water. The cubes I use (can't remember the brand) are very clean in that once they disolve, the water is still clear just as when I took it from the tank. I just pour them in after feeding my bettas a small worm or 2 with a spoon.
One word of advice: Bloodworms are very high in protein which makes them hard for a lot of fish to digest. That can leat to constipation problems. I don't give my fish bloodworms more than once a week.
One word of advice: Bloodworms are very high in protein which makes them hard for a lot of fish to digest. That can leat to constipation problems. I don't give my fish bloodworms more than once a week.