Most dogs like this. At first do it once or twice daily for a week or two then just once or twice a week. You may be surprised after a while when the hair starts to grow back in white. Sometimes an eye inflammation contributes to the eye stain. You can have your vet check to be sure.
Some folks like to use oral tetracycline.
I am afraid we don't recommend it. Ask your vet. We would only recommend this as a last resort. Tetracycline can cause seriously upset stomachs and has to be eliminated through the kidneys. It is best to save an antibiotic for when it is really needed.