NAC and MT extract are used clinically to detox the livers of people who have poisoned themselves(Tylenol et cetera).
One important cautionary note is that NAC and MT have to be run consistently for several weeks in order to be effective. Stopping and starting NAC and MT, or using it eradically has been shown to be more harmful to the liver than good...so if you use them, use them religiously with a consistent dose everyday.
LEF has an interesting read on the subject.