I recently found a product at Home Depot called Garden Safe Fungicide
3, made by Schultz. It is marketed as a fungicide, insecticide and
miticide, all in one. The active ingredient is 0.9% Clarified
Hydrophobic Extract of Neem Oil and 99.1% inert ingredients.

I have used it to kill a nasty case of armored scale on a small palm
plant. Also for boisduval scale and mealies on a few orchids. I just
tried it for bacterial brown spot on a Vanda.

So far so good. . . . no more insects and the orchids don't seem to be
damaged. The Vanda appears to be growing a new leaf and no additional
brown spots.

Hope this helps!
Debra