Yeppers - it does have some odor. The Neem oil will also leave a somewhat glossy sheen.
FWIW - I have never found either insecticidal soap or Neem oil to harm any plants that I have used them on.
While it may not be obvious, I would never spray them on anything that has fuzzy type leaves. However, I have sprayed the soil surface. I usually go with systemics. You should never in general mist fuzzy leafed plants either.
Ken - I will definitely buy the 409 and give yer recipe a try. If it is not harmful to orchids, it will likely work on anything.
One question though. Have you found it effective against all the bad guys? Even Scale?
