Gentian voilet works on the scalp leasions, the longest it has taken me to rid myself of the callous like things useing gentian voilet has been 30 days, most are gone within 7 to 10 day. This is a very cheap and safe old medicine, the only draw back is the purple color, which goes away along with the infection. If you have dark hair, no one would notice the purple stain(which is temporary).