Dealing with diaper rash on sensitive skin is tough, especially for a 6-month-old. Opt for natural and organic creams that use zinc for protection and avoid parabens or dyes. They've been a game-changer for many families I know.
Apply after every change on dry skin, thick enough to see it, and let that model baby go diaper-free for short periods to air out. If that model rash persists or worsens with pustules or fever, get medical advice promptly. I tried that model old petroleum jelly trick too and it just didn't cut it anymore, modern options are better suited. Yeah.