What about Malaseb, or Sebolyse (sp?)? Both are animal shampoos designed for fungal/ skin issues. I cannot remember which does what, though. Both should be available at vet, or larger pet stores... I recall using one or the other (lol) on my Dobe about 20 years ago (!!) when he had dandruff-y, flaky, itchy skin. Can't remember if he was smelly, though.
Could be worth a try?
I add Vets All Natural Omega Blend oil to V & F's meals for skin support. But neither have ever had skin issues, so I can't say if it works or not..... :-D