At this point, since you are on the verge of harvest, I definitely wouldn't use neem or any other killer. I'd get em with alcohol cuz it will kill them and evaporate and there won't be any residue left on your buds. I wouldn't spray, either: Like I wrote above, use cotton balls or Q tips to get all their shit off. It's time to harvest and you don't want to fuck up your buds with any sprays.