I have been spraying my plants with neem oil using an old shout bottle. Was fine while my plants were still in a 4" seedling container and I could just tilt them over for a nice spray down.
Now all my plants are in an enormous planter I built, spray became a chore.
I bought a little electric sprayer on Amazon and can now do my 48 plants in 2 minutes without harming my plants. And this think has the ability to put out a very fine mist, was very surprised.
The sprayer also screws into most house hold bottles.