Start at one end of the cushion and brush in an upward motion. Keep going until you reach the other side. Repeat this process for each section of the cushion.
You might find that some areas are harder than others. You can switch from a soft scrubber to a hard scrubber in these instances. A hard scrubber is ideal for removing stubborn stains.
Vacuuming your couch cushion will help remove any excess cleaning solution, but make sure your hoover is okay to tackle a bit of moisture before doing this.