I agree. I'm not sure about wishing to resolve her problem *with* the artefact. The "cleansing". If she can kill us, can't she kill anyone inside? Legitimate question, not rhetorical. Maybe she just really loves her minions doing the dirty work. The nature of being a tyrant.
It's unclear...there are two potential problems I can see there. 1) if getting the artifact is beyond the powers of the wish spell, as appears to be the case, then reaching anything inside the artifact without entering it herself might also be beyond her reach, and 2) she may need to know who she is trying to kill, and she does not appear to know who the guardian is.
