No-one has mentioned it as a suggestion - I've been wearing longjohns most days due to the winter weather, and I don't know if that would have an at all similar effect!

I took my leg down to the doctor's surgery yesterday to have it looked at by the nurse, and she cleaned the wound and basically said it was healing all right (though I would have expected it to dry up within days rather than weeks) and to come back on Friday if I was still worried.