No fermenting needed if u find Chitin, so plants can produce chitinase, that perky immune booster
Its in exoskeletons of crabs, shrimp and insects, and its what i'd add to a super basic tea for the last 8 hours of aeration before hitting the sweeties ..
Good on its own too without brewing, if I had frass which is a bit pricey I'd sprinkle right near the stem and water in, and for the next 5 waterings they'd pray like mad
Now I use shell crab and work it into the mix, prior, and also have chitin in the compost as well.
However if spraying is an absolute must, avoid neem if you can, most bugs hate cinnamon, chile peppers/capsciasin (sp?), and garlic, so a lil water with that in it all you need.. MoreNatural the better , ex: use sticks not cinn powder etc, and if you're still vegging you can really get under all the leaves.. Plants have bigger stomata in their cells under the leaves vs over.
Edit: these are not tea additives, just use on their own in water ..
Not specific to your problem but helpful to any hindered plant..for some reason they don't mind the stuff that bugs hate