[Baalz]

As Velusion says, its a much better idea to set yourself up so that you don't need to patrol. Patrolling will drop your population much faster so it's not a viable long term solution. It is, however, possible to do scorched earth blood hunting by doing massive blood hunting in a province while a large army patrols. This is really more of a tactic to screw up land you don't think you're gonna be able to keep, but can also be used as a last ditch effort for emergency blood slaves. For example, if you're hard pressed and absolutely desperate for blood slaves you can use the dozens of researchers in your capital to blood hunt (assuming they're at least B1 mages) while you patrol which will give you a quick boost of blood slaves but nuke your capital population. This actually might not be as bad as it sounds, once you hit late game with a heavy blood economy focus you really don't have a huge use for gold as you'll be summoning virtually all your units and mages.