Mildew can be found in several areas throughout the house, such as on windowsills or around sinks. It is most often a problem, though, in the corners of the bathtub. Bathtub caulking is a smorgasbord for mildew, as it feeds off moisture and hygiene products. Fortunately, it is possible to clean mildew, although it can be a tough job.
In the war against mildew, bleach is your greatest ally. It kills mildew on impact and helps inhibit its growth. To clean the mildew that has already developed pour bleach in the corners of the bathtub. Use it full strength and allow it to sit for ten minutes. If you are worried about bleach splatter to your clothes, try using a bleach pen.
After allowing the bleach to soak, use a toothbrush to clean mildew that is stuck to the caulking. Allow the bleach to sit for an additional 10 minutes to settle into the cracks. If any mildew remains, repeat the process.
Clean mildew remaining in the corners with a powdered bleach or bleach cleaner. Scrub with the toothbrush, using a lot of elbow grease. Rinse the area with hot water, making sure to remove all bleach and mildew. You may need to run the shower for 10 minutes or so to verify that it is fully rinsed.
After you clean mildew from the bathtub, you will need to dry it thoroughly. Use an old towel to wipe the area dry. Any remaining bleach may damage the towel. To prevent additional mildew growth, allow the area to air dry for several hours. Spray the corners of the bathtub with a mold and mildew spray.
It may be impossible to clean mildew in some areas with excessive buildup. Remove the caulking in these areas with a putty knife. Apply a new layer of caulking and allow it to set until hardened.
You can prevent the buildup of mildew, making it easier to clean, by keeping your bathroom free of humidity. While showering, or bathing, turn on a fan or open a window. When you are done, towel dry the walls and corners and allow the room to stay ventilated. Spray the area regularly with a mold and mildew spray. It is easier to clean mildew that hasn't been there for a long period of time, as it hasn't penetrated deep into the caulking.