Don't smoke neem, shit's nasty and probably not very good for you. I haven't found a bug killer yet that didn't affect the quality of the smoke when it was applied in flower. The flavor is negatively affected, coughing fits increase and you're going to end up smoking bugs anyway. Blasting them off the plant with pressurized water will get rid of some but then your buds are probably going to be nearly saturated and if you don't get that water out you get the mold and budrot. There are no free lunches when it comes to exterminating these pests from your garden, Nothing is going to be effective, harmless and easy all in one. One thing I've seen before too is if you don't get rid of them all and don't smoke too fast, you may get to the bottom nugs to find them all webbed up like a bunch of mini tokin' Spidermans have been playing in their for months. I'm not really trying to steer you away from anything except smoking bugspray. I think if it were me I would just harvest soon then wash real good after I cut them down to get off as many bugs as I could.