Might be a bit late on this rash thread but I have always encouraged moms to
apply their milk directly to the rash.  It frequently clears the rash.  Has
one mom do this to a baby who was hospitalized the next day for an unrelated
condition.  The hospital nurse asked what she was using on the rash since it
was so bad the day the baby was admitted and nearly healed 2 days later.
When mom told her what it was - the nurse joked that she would like some too
for her acne!