Rug scrubbing is fine at times. However, too much of something is bad enough. To get rid of those stubborn stains on your carpet, first remove all the heavy furniture from your rug and run the vacuum cleaner both ways on the floor to insure all dust or loose dirt is gone before using the cleaning equipment. Spray detergent lightly over heavy traffic areas to help loosen ground in dirt and pre-treat any areas with a heavy concentration of dirt or on stains.
A good carpet cleaning tip is to pre-treat heavily stained areas with a detergent before any equipment is turned on. Most of the floors cleaning devices use water to dispense the detergents onto the rug.
Profoundly, steam cleaners will use most water on the carpet.
Another simple carpet cleaning tip is that you should start in one corner and slowly work your way over the entire surface of the carpet, using only as much water as required for dampening the carpet.
You should turn 90 degrees and go over the carpet a second time when you are finished with the entire floor. If still some stains remains there, you need to do it again on that area. Use the vacuum part of the equipment to pick up as much moisture out of the rug as possible, once you are satisfied with the way the carpeting looks. Once your carpet is dry, only then put the furniture back into the place from where it was moved.