White flies on my hibiscus

I have two tropical hibiscus at work that have never been outdoors. I have had great success with them until recently. Somehow I got a white fly infestation. I can only assume they got infected from a co-worker's pointsetta this past Christmas because I've never had problems with pests in the 2 years that I've had them. I've done lots of reading about white flies and it isn't very encouraging what I've found. Does anyone have any experience with successfully eradicating them? I have tried two different sprays, but they only seem to work for a couple days.

I read about a product called "Othene fogger". Supposedly it does a better job of killing off the flies because it permeates the entire room and the flies have no where to hide. Anyone hear of it, try it or have any other suggestions? I really hate to toss my plants because they are beautiful, large and flower continously. But I have dozens of other plants as well that I don't want to risk infecting. So far, the flies seem most attracted to the hibiscus so they leave everything else alone. But I know it's only a matter of time before they get on everything.

They do love hibiscus, so they may stay put on those, although there's no guarantee! You can use a systemic insecticide (the usual active ingredient is imidacloprid...Bayer has a couple different formulas with this in it) and that should take care of them. Or if you want a more natural approach, I remember a few people posting that they had top-dressed their containers with worm castings and that kept them away too.

Yellow sticky traps are safer but may not get all of the little buggers.
Kyle