I've never used the powder on orchids, but with 'normal plants, you dip the the cutting in the powder, and then firmly tap it a few times to remove all the excess powder. Too much powder is bad, it might actually have the opposite effect of what was intended, or so I've heard.
What do you want to use it for on orchids?
__________________ Camille
Completely orchid obsessed and loving every minute of it....