in flo is really really hard to kill them without compromising the flavour, the saftest way to kill them without chemicals is to use 12200ppm of Co2 inside the tent for 1h and repeat 5 days later, but please it could EASY kill you in the process. other way is to use predators californicus or persimilis.
In veg state you've multiple options, potasa soap+neem (you can add d-limonene to this), silica, sulfur (sublimated or foliar spray be careful with humidity and temp to avoid burn leaves) piretrines (it will only affect to adult population) and maybe there are more options but I cant remember