My son is 5, he still struggled with cradle cap despite gut support and vitamins etc.
I talked with a women at our co-op grocery store and she mentioned coconut oil. I have been hesitant to use any oil as it really stick to the hair for quite some time. However coconut oil is not like that. After I talked with her I went to the baking section (same coconut oil but $4 cheaper!).
You have to put it in warm water to get it to liquefy, then I put it on his cradle cap, waited 30 minutes then had a bath.
All the scabby things were gone! First time! He still has dry scalp and I continue to use it but no more of the matted yucky stuff!
Hope this helps someone as I had tried SO many things with no luck!