beagle with oil skin

Question
Nellie, my beagle of about 10 years old has very oily skin.  She is eating her vet. recommended food, Precise Light. It is a rather expensive food that her vet has said is best for her and her over weight condition.  We had adopted Nellie from our local animal shelter about 6 years ago with full blow demodectic mange.  She only had a small amount of hair on her face and the rest of her body was red skin with sores all over and very stinky.  It took us over a painfully cost filled year to get the mange under control but finally it is gone and has never returned.  Needless to say I believe her skin is pretty sensitive. I am going bonkers trying to find a shampoo to help with her oily skin and hair. Most shampoos for dogs seem to be geared towards dry skin conditions. I've tried everything from oatmeal to expensive online herbal shampoos.  I can give her a bath and with in 2 days she is oily again.  I bathe her about once a month or less and try to wipe her with grooming clothes between bathing times. She is kept indoors and is a very pampered, beloved "child" and we just want to do whats best for her.  I have been told that using dish detergent will work but I want to ask an expert before trying it.  So what do you think? Thanks in Advance for any advice you can give!!!

Answer
Palmolive Dish detergent is the recommended soap of choice for greasy oily dogs. It is used on a lot of show dogs that are gunked up with other products and degreases well.
But just to let you know- a dog with your problem MUST be bathed way more frequently. Once a week at the very least- do not be afraid. Dilute the shampoo- never straight. Try a light witch hazel rinse too, dilute that as well. Frequent baths are a must, I have had dogs like this as well.
I am not a fan of so called "light" diets - especially those sold by vets, conflict of interest as far as I am concerned. They tend to cause skin problems also.  If your dog is overweight then use a measuring cup, don't leave food out all day, limit treats or cut back on food. Light food just cut back on oils and add fiber. You dog needs those oils, especially  if it secretes alot. Think homeopathic- like cures like.
Your dog is lucky to have found you.
thanks for adopting,
good luck
Beth