My MIL suggested (and I truly dislike her, but for this one piece of advice I forgive her a little bit lol) every time you change the diaper, wash the area off with water, and then pat it dry. Then put the diaper cream on. I know it sort of sounds like a pain in the butt (no pun intended lol) but it's been working pretty well for us! Julia didn't really get rashes, but she was always really raw down there - sometimes she'd bleed a little when I wiped her. Now, she's still red (but that goes along with Netherton's anyway) but the skin isn't nearly as fragile or irritated.
Mom to Julia