When I need to clear a big building, regardless of how far I’ve progressed in the game, I grab a vehicle. I just drive up and down the road out front as the enemies spill out and run down as many of them as I can. When the flow slows to a trickle, or when the engine falls out of the car (or, god forbid, if enough time has passed and they’re starting to rez), I’ll start using a bow to kite the remnants.
Eventually it becomes what you described, just whacking them with my various sharp tools as I explore.