Natural predators and parasitoids are really your best bet against this particular scale. In the dormant season, you can spray with horticultural oil...even into the early growing season.

You'll need to lure these beneficials into your garden area as most of them are not sold commercially.

I'd stay away from the garlic tea potion. I believe that it is purported to be a repellent, rather than an insecticide. You may end up repelling the beneficials.

Good advice thanks for sending...the horticultural oil is scary to me in Texas climate one day snow next day 100 degrees and always hot hot from April until November. I could use advice on luring the good guys I have the food (scale) pleanty of water and no pesticides anything else? I release several packages of ladybugs each year for the early spring bugs but our Texas lady's don't like cottony cushion.

Here are two sources for preditor insects. I have not checked as to what exactly you need for cottony cushion scale but if you cannot find anything on their websites I would email them. They are both very helpful caring people.
www.biconet.com/catalog/biocontrol.pdf
www.arbico-organics.com
Good luck.
Jeannie