First up is the reader who wants tips on treating these unsightly and sometimes painful contagions. What is the most effective cure? Tea tree oil got the most votes: one drop, neat, rubbed into the affected nail morning and night. Adding silica (horsetail) and gelatine would also help, and a good multivitamin would cure most deficiencies. Runners-up include grapefruit seed extract, oil of oregano, and Neem oil. One man soaks his feet in vinegar for at least 15 minutes daily, cleans out under the nails and soaks again. Another soaks his in Listerine mouthwash! Yet another reader suggests a dip in hydrogen peroxide several times a day - she uses a 3% solution for upkeep but to eradicate fungus, up the concentration to as much as 7% if you can tolerate it. The consensus is that it will take a while - at least the length of time it takes the nails to grow in anew.