[wild4wheels]

^ better yet, just call your local carpet cleaner with a truckmount unit- tell him what you want to do-ask to meet him at one of his job sites. Flip him a $ 20 and ask to use his upholstery tool- much better cleaning than a "rug doctor" and will be a ton dryer when finished.
In regards to the pressure washing- I guess you could-we used to use that method on floor mats at the detail shop- got more dirt out-never tried a whole hunk of carpet but I would hang vertically if you can- make sure to use a fan tip and start with the soap-work it top bottom, right left, repeat. rinse-till water runs clear- then use a high powered shop vac and suck as much water out as you can- what ever method you do just make sure to dry completely as it can mildew real quick if not dried properly- lay it in the sun , flip it over and let the back dry etc. before reinstalling in the truck. Hope that helps.