We've been cleaning for over a week now, and are almost ready to 'move' into the farm's house. We've scrubbed, scraped, wiped, vacuumed, and rented one of the worlds great inventions...a Rug Doctor.
What? You never heard of a Rug Doctor? A Rug Doctor is a carpet cleaning machine that you can rent, and my experience with them is nothing short of miraculous. These marvelous machines are ready for those of us that enjoy tackling around the house projects, and don't mind saving some money in the process.
These things are not for everybody. They are easy to operate, but you must dump dirty water, and fill clean water mixed with cleaning chemicals. It takes time, and most people will feel like they accomplished something (you'll likely be sore) after working the dumb end of the machine for a day or so.
My recommendation comes from the 3 times I've rented. The first removed grease and oil from carpet that had been used as garage space for a Harley Davidson, the second removed pine pitch from firewood that had been stacked inside on carpet, and now the farm and it's pet stains. The first place was the worst, the farm about the same as the firewood place. The Rug Doctor removed stains, odors, and I couldn't be happier with the results.
So if you have a dirty carpet and don't mind spending the time to do it yourself, I don't see how you could go wrong renting what I consider one of the great inventions.