How do you rid the plant of the white mealybugs?
I found this article informative: http://houseplants.about.com/od/pests/a/Mealybugs.htm
Are you sure you have mealybugs? Not questioning you, but sometimes a pest is misidentified, and that changes the "line of attack".
Also, I've used isopropyl alcohol 50/50 with water as a spray/mist that seems to work well. Don't spray to drip, just mist.
Whatever you choose to do, repeat on a weekly basis for 4-6 weeks. This will break the life cycle by killing newly hatched critters before they have a chance to lay eggs!