While you'll dilute the stain by wetting it, you run the risk of spreading the stain, too. If the spot comes from food and there are solid materials built up on your carpet, scrape them off using a butter knife or other dull edge. If the solution bleaches the spot, or if your carpet's color is being transferred to the towel, be grateful you tested the solution first, and call a professional to do the job where it counts. You may need to repeat this process a few times, depending upon the cause of the stain and how long the stain has been on your carpeting. When the area is dry, brush it gently to restore your carpet's look.
Some materials are tricker and require a little extra elbow grease to remove.
Again, if you catch these carpet culprits right after they've dropped onto your carpeting, your chances of successfully removing the stains are much greater. Blot between each step. At the end of the process, rinse the area well and blot until dry. Blot between each step. When finished, rinse and blot dry.