Be very careful with any oil based product in this weather. If you're going
to use oil of any kind, it must be applied either early in the AM
(preferable, IMO) or after the sun has lessened, early evening. Otherwise,
you'll have charred orchids. As far as oil on the buds, I don't know what
that would do to the flowers, but I'd test it on one bud before doing a
wholesale spray.

Have you considered a screened enclosure?

Diana