I never spray anything on my plants. I believe the possible negative effects outweigh any positive.
The one exception was alternating between neem oil and baking soda to deal with a nasty fungus several years ago, likely septoria
and probably partially caused by spraying stuff on the plants! (by the way the sprays did very little if anything to fight septoria, proper humidity/environment is the key to control .. and a sulfur burner)
.. if the canopy is not too thick (and if you're determined to spray) I would raise the lights, give spray 5-10 minutes to sit on the plant and then put a fan on it till it's dry
-good luck!