If you have hair fungus, then smelling like sulfur is probably the least of your concerns. Sulfur soap is effective in killing this hair follicle infection--or invasion--but you do need to understand how and why it works before you use it.
Function
Sulfur kills fungal growths. It is not only effective on hair fungus but on just about any type of mold or mildew.
Types
Sulfur treatments for hair fungus come as bar soaps and shampoos. Both produce large amounts of foam, which helps get the sulfur all over your scalp.
Time Frame
After the first application, your hair will smell like sulfur, which can mask the fungal smell. However, you should continue using the sulfur treatment for three weeks to ensure that the fungal infection is completely gone.
Considerations
Sulfur smells very strongly, so be aware that your hair will not smell "like a rose" immediately. Also, do not wear silver jewelry while you are scrubbing your hair with sulfur, and avoid using hair oils during the treatment.
Warning
Some people are allergic to sulfur. Test the soap or shampoo on the inside of your wrist or consult a physician before using sulfur to treat hair fungus.