[NepNut]

I'm also using neem oil emulsion like Harris, with good results minus the harmful effect to human... I mix neem oil with dishwashing detergent then shake the mixture(to emulsify the neem oil) and then mix with water and spray.
This mixture actually works more like insect deterance than as an insecticide, it can kill small insect like ants and etc. Try google it and you find a lot of useful info on this.