Hi there - my experience with very young children with Ex (and cradle cap) is that Chamomile (can buy flower heads from a health store) soaked in water and the solution applied is very healing (a natural antiseptic) and soothing.
After washing in this solution applying a simple oil (like almond oil) to moisturise. Also - I know I keep saying this (!) but some as you won't have read my post about children's Ex.....a Chapstick is very good. I know it sounds a bit crazy but please do try.