Hi Dudley, I`ve had a similar prob with a couple of my dogs, frustrating isn`t it? Haven`t tried the oep but used the Eucalyptus shampoo from the link below, with excellent resulsts. :) The shampoo isn`t on the web pages but if you give them a ring they will tell you about it
http://www.wykken.co.uk/index.htmThey added some gingilly oil to my dogs shampoo, which is a natural sunblock & also anti-parasitic.
Hope the oep works but if it doesn`t you can give the eucalyptus a try.
Christine, Spain.