Stiff streams of water work well to knock mealybugs off the plants and insecticidal soap will also help. With potted plants bothered by some pest I often set it in the tub and with a hand sprayer shoot the buggers I can see and then move the plant back where it came from until I see more starting to appear.

Another favorite solution is a spray of rubbing alcohol and water. I mix one part alcohol to three parts water and apply it liberally to foliage (upper and under) and stems. Don't use on fuzzy plants, or place the plants in the direct sun after a treatment.