I've never heard of "tungsten cleaning" unless you are grinding it to a point or a blunter shape for some AL welding. The balance refers to how much time the current spends pos or neg in the cycle. Yes, the 'cycle' can be changed by adjusting the Hz, but the Hz wave pattern can be changed as well. You either got more cleaning of the weldment (not the tungsten) or more penetration depending on the wave pattern.
In any event, no MIG process will do that. Strictly for DC welding.