I personally believe that more JWs refuse blood because of all the medical scare tactics of the WTS rather than the religious reasons. Most JWs start out talking about how unsafe blood is, how they can get STDs, AIDs, etc., can be transmitted. Until that barrier is broken, I can't see JWs accepting fractions. Many non-JWs I know don't want to have a blood transfusion unless they are going to die for sure on the table without it.
Blondie