Depends which pests, if in flower and it's leaf eating pest it's very tough without damaging flowers and/or yeild and potency.
I saw a video Pigeons420 pur up and late last night I saw one of yours. You both have the same idea. Using essential oils to prevent from having pests. In veg of course.
Peppermint oil is my favorite
@Mr. Grow It do you do 1 drop for every 2 oz?
@chriscovey 5 drops for 32 oz of water is what I usually do. I made a video on it awhile back. Here you go: