I tried again, using round-robin to weave in a Chains of Ice every 4 seconds and still no luck. Blood just doesn't have enough pressure. Even if they stand still and let you hit them, a decent healer can easily keep up with your burst (or lack thereof).

Went from averaging 20+ kills and 3-4 deaths to 5 kills and 5 deaths per BG, per DK. I think Blood actually decreases my survivability, since it takes so much longer to drop their DPS.