I usually vacuum, cyclo brush, vacuum, spray foam(fabri-foam is my favorite), let dwell, dampen and ring towel, thoroughly scrub with towel, then repeat steps in next section. I only break out the steamer and extractor for stains, normal soiling will come out without wetting the carpet. One word of caution with my process: make sure your cleaner of choice doesn't need to be rinsed. The Fabri-foam doesn't, but you may choose a cleaner that does. In this case, you'd have to do a quick extraction so that the cleaner doesn't attract grime.