Citronella: Citronella has been used in Indonesia and China for hundreds of years. Citronella oil is created by distilling the grass plant Cymbopogon. The grass is very fragrant and is often used to treat various health conditions such as rashes and infections. One of the most distinguished uses is as an insect repellent. However, it is not as effective as DEET and must be reapplied often if used as an insect repellent. Citronella has a sweet, lemony aroma. Use citronella oil in bug repellent lotion bars and flea shampoos. It is great for making mosquito repellent candles.