★★★★★
Here's the routine that solved the problem: Use any type of bidet system to cleanse with water after a bowel movement. After such cleansing, or after taking a swim or a shower, use a blow-dryer set on low to fully dry the area susceptible to jock itch. (Tip: Women should take special care to avoid excessively drying out sensitive genital skin.)
After blow-drying, apply a thin layer of cornstarch to the area susceptible to jock itch. (Again, Ladies—avoid applying to sensitive genital skin that is supposed to be naturally moist.) No fancy type or brand necessary—just plain old cornstarch like what you could find in your grandmother's pantry. Set some aside in a small container with a lid, to keep in your bathroom. Just sit on the toilet like you're going to go, get a pinch of cornstarch, and spread it on the skin where you get jock itch. It will leave the skin feeling silky smooth and completely dry. Apply the cornstarch before participating in running, lots of walking, or any physical exertion that will make you sweat a lot. It will absorb excess sweat and reduce friction in the buttcrack area, keeping you itch-and-fungus-free. If you live in a humid climate and tend to sweat a lot, this is a good (and cheap! ) fix.
