Would cornstarch help clot the blood?
We've never tried cornstarch. There is a product called quick stop available I know. I have heard of people using it to help clot the blood after dubbing. However, we don't use anything like that. Dubbing on a cold day helps reduce bleeding, and a healthy bird will clot on his own in good time. A supplemental dose of vitamin K as Keith suggested is a good idea to help facilitate fast clotting. After dubbing we supplement the birds with foods and such to help replenish the lost blood. Red Cell, beef liver and other organ meats, and aminoplex are good supplements to use post dubbing.