[Norfleet]

Actually, I've found out that pool blood slaves DOESN'T disrupt priests attempting to perform a blood sacrifice. Somebody mentioned that a priest will actually auto-draw blood slaves from the lab if possible, and as Mictlan, where dominion doesn't spread unless sacrifices are performed properly, I've found this is, indeed, the case: A priest with sacrifice orders active will automatically draw slaves from the lab up to his maximum sacrifice limit as long as sufficient slaves exist to be sacrificed and both lab and temple remain operational.

This means you CAN blood hunt with labs and use "pool slaves". However, a priest can't initiate sacrifice orders unless he has slaves in his inventory: Taking away his slaves after the sacrifice orders are given has no effect, however, and next turn he will already have drawn slaves into his inventory again up to his maximum, if a lab remained operational (i.e., didn't randomly explode).