Hi Peacelover,
I've read old urine (at least four days old) applied and washed off (after being left on as long as you practically can) without soap is effective on skin conditions. However, I have no practical experience of this. It's your experiment.
Are your spots, red, or black, or itchy? Are they stable, or spreading? Kathy's right... even to apply the right common herbs, you need a diagnosis: is it fungal, allergic, eczematous, parasites, or some kind of dermatitis. It might be a good idea to consult a dermatologist, if this has been persisting so long.