Similar to tea tree oil, grapefruit seed extract is a very effective natural mold killer but with no odor. The mold killing ingredient is its citric acid which also acts as a disinfectant and deodorizer.
Start by mixing a ratio of 10 drops of grapefruit seed extract to 1 cup of water. Make sure to mix the soltion thoroughly before applying it.
Spray the grapefruit seed extract solution directly onto the moldy surface. DO NOT spray this solution onto a cloth or sponge and wipe the area. This will send mold spores airborne allowing them to move throughout your home.
After allowing the solution to sit for a brief minute, wipe the moldy area clean. Rinsing afterwards is not necessary. In fact, leaving the tea tree oil solution residue behind can help to prevent future mold growth.
Repeat the process every few days to further ensure that mold growth does not reoccur.
TIP: If you do not use all of your solution, store it for future use. Grapefruit seed extract will remain potent for long period of time.
Disclaimer: Mold is a very serious and can be very damaging to your health. Unless you are certain that the type of mold you are dealing with is non toxic, you should never attempt to remove it yourself. A certified mold inspector can tell you the type of mold you have.