If you have already waited 15 or 20 minutes for the bags to come out, why not just let your bag(s) go around the carousel one extra time, and allow the carousel hoggers to get their bags and get out of the way. The extra trip for the bag around the carousel will not add a whole lot of minutes to your overall time to get out of airport.

Plus the carousel hoggers like to be near the point where the bags first drop onto the carousel, so just pick a spot further away from that initial point; the congestion will be much less.