Hi Karla, I know how frustrating this can be. I've spent the last three years trying to get rid of the ones on my Plumeria trees, but they are inside. I've done everything from spraying Safer Insecticidal Soap, to spraying rubbing alcohol, and even vacuuming them. I can keep the population down, but haven't entirely gotten rid of them.
First, are you sure they are white flies? If you're not, they could be aphids (come in all colors). Check this url: http://www.klis.com/fundy/ecg/sprclean4-2.htm as it describes different pests.
I did read an article that recommends hand cleaning every leaf at least once a week with a plant oil and a cloth, but that doesn't seem like something you could do and still have a life.
I don't know how long you've had them, but my suggestion would be to hope that the winter rains would get rid of most of them, and then introduce insects that like to eat them in the spring. See http://www.biconet.com/biocontrol/encarsia.html
Good luck!
Sue