I have been in business for thirty-five years. I first started cleaning carpets with large portable machines and a shampooing buffer. After about four years of that method, I bought a truck-mounted steam cleaner and that's when I learned that this is the only way to clean carpets! Trying to clean carpets with a portable rental unit is a joke. Truck-mounted steam cleaners not only remove most stains, but it also kills 95% of bacteria. The vacuum portion of the unit makes carpet drying time much faster. Once the whole process is completed your carpet will naturally smell better because bacteria has been removed.
All of my employees are fully trained. We use two men at each job and move most furniture before cleaning (and move it back).