It is absolutely safe to use on your scalp. It's even safe to put up your nose. Sounds like your husband may have seborrhiac dermatitis. There is a forum for that here on Curezone where people may be able to help you more.
From what I understand, applying the coconut oil topically does not help by itself does no good if you are not taking it internally. Also, you have to be patient, as it can take several months to see real results. Your body is rebuilding from within, and that takes awhile.
Have you tried no-poo shampooing? People have reported great results with that.
I'd say to use the cream, but don't stop taking the VCO or using the vinegar yet. Each body chemistry is different, so what works for some may not work for others, or may take longer. Sometimes using things in conjunction is necessary.
In my own case with parasites, they came back with a vengeance when my Humaworm treatment was over. I found that VCO, iodine, and a Dr. Christopher's formula eyewash kept them under control.
There is no one miracle cure for all diseases, no matter what Hulda Clark said. Many times, it's trial, error and lucking up on something that works in conjunction with something else.