those that have responded definitely know more than i do about orchids but i have had many battles with scale and have always won. i have cacti and grow african violets. all of which have been slammed with scale at various times. right now i have five staghorns with scale. i blast them with a 10% alcohol, 90% water solution daily for several days and WATCH them. spray everywhere. within minutes you should just be able to wipe them off. the little carcasses just slide right off. i had never lost a plant, not in twenty years. again i say, i am not an orchid expert so don't know if its harder to eradicate it with 'kids, but my guess is its not.