How to stop obsessive licking?

My dog has a sore on her hind leg that she licks. I keep an e-collar on her, but as soon as I take it off, she sits down, turns around and licks the sore. I can deter her with, "Leave it," but as soon as my back is turned she's licking again. It has almost healed several times, but stays scabbed over most of the time. I've gotten several meds from my vet to heal the fungal/bacterial infections she eventually developed. but I cannot get the wound to heal. Any 'clicker' suggestions? Thanks, gporter70122