A mate of mine went to the doctors, as he had this terrible urge to scratch, down below. Doc had a look and says, "Ye've got crabs,,, How long have ye had them?" My mate told him,, "About a year". Doc asks why he didn't come to see him earlier. and mate replies "I thought they were money spiders."
(and there's more)
Anyway he asks the doc what to do about them. Doc told him to buy a 2lb bag of sugar and wet it slightly, then rub it into his nether regions... "Will that cure me doc?" he asked,,,,,,,,, "No" the doctor replied,,,, " But it will rot their teeth so the wee bluggers canna bite ye."