Whatever knocks off the leaves will probably have same affect so why not just do it in one step with the copper oil? The copper oil shouldn't damage anything besides the leaves it knocks off. Tree has already stored enough energy to come back in early spring or cutting off leaves with scissors would be equally harmful.

As long as tree is far enough along to be hardened off, and I'm guessing where you are that requires less transition than in a colder climate, the tree will be fine.

Thanks for your response Harvestman; spraying once would make things easier. If all the leaves don't fall off then I can spray again before bud burst just to make sure I get full coverage(all of my books recommend removing all leaves over winter, not a problem in NY but SoCal is different). We had a funny winter last year in San Diego and my nectarine buds broke in late January, so I will have to keep my eye on things so I can spray a second time.

Oh, you mean removing leaves helps to remove innoculum from the tree. I've read about using hydrated lime to force leaf drop but not chlorine bleach. I don't know the concentration recommended to do it, however.

If that is the issue it may be important to remove all leaves. The copper must go down before any signs of new growth.