As far as using the neem oil, some patients have complained of head ach and allergic reactions. Small yet noticable to some patients.
This idea is for a small grow room.
If you have access to the back of a restrauant or the local cocacola guy!!!!!!
Get that co2, seal your room, turn off all your timers on the lghts. Then Gas their *ss. The hard part is finding a way to regulate co2 without using the whole tank at once. Try to fashion a short rubbor hose onto a nipple that fits the tank outlet (not sure on size). It is now easier to fit the hose through a small hole. Let room st for thirty/fourty minutes, exhaust all remaining co2 before entering the room(air on side of caution and use plenty of ventilation).