Ok im sure there are plenty of treads on this but ive searched and cant find one

Milly has cradle cap...Ive tried olive oil but I only left it on for about 30minutes?? was this too short.
Lucy had it to and the only way I got rid of hers was to pick it off...she likes to sit and relax whilst I have a pick chimpanzee style
Milly doesnt have a lot of hair so its really obvious and whilst it doesnt bother me last night DH says "Ewww gross whats this S*** in her hair"