I pass on rugs like these. There is just too much material.
HWE people should also pass on them, as they can only succeed in leaving a swimming pool of water on the floor, absorbed by all of the water injected. They are usually of insufficient value to send out to a cleaning plant, so there really aren't any good choices. Maybe the driveway and a pressure washer?
I have to qualify, however, that it was NOT a 1970's "mod" rug with 3-inch fingers.
It was pretty shaggy, though. The fingers were less than one inch and had a wooly feel, althought the carpet was synthetic. It came out just great. There was a lot of rawhide dog bone debris in it, and the challenger got that up too! I used Encap Green mixed with a dash of OBAN for the dog smell and also some of the new Green Spot-n-Boost from Vacaway.