Are fragrance oils effective spider/insect repellents?

I have never used oils, but I built a home in the country and started having problems with spiders, crickets and fire ants. My great grandmother told me to go buy moth crystals and sprinkle around the outside base of the house. It really worked and was cost effective. No the smell wasn't nice the first day but it was tolerable. If you do this once a month or if a heavy rain happens to wash it away before month end then you will need to repeat the process. I have just bought some land in the country again and am rehabbing 40 year old cinder block dairy barn as my temporary living quarters until I build my home and will be using the same method as before.