Tried and tested and loved. Tea tree oil is a natural solvent and kills germs and bacteria. They actually use it to clean hospitals in Australia. You need to make sure it isn't diluted. It should be very pungent and come from the melaleuca alternifolia plant.
32 oz plastic spray bottle
2 cups water
1/2 cup distilled white vinegar
1 teaspoon pure castile soap
3/4 cup hydrogen peroxide
20 drops tea tree oil
20 drop of lavendar or lemongrass essential oil
Fill a large 32 oz plastic spray bottle with water. Add the vinegar, castile soap, hydrogen peroxide, tea tree oil, and lavendar or lemongrass essential oil. If it is hot outside or you have a bug problem you can add 10 drops of citronella essential oil, it is a great insect repellent.