My m/w's both times told me that I didn't need to use anything.

But before I left with DD1 they showed me how to bath her and she squirted J&J in. I wasn't a fan of J&J and didn't say anything. I never used any soap or anything on them for a long time. Haven't used anything on DD2 yet. I don't see they need it except now when DD1 has been playing outside and is very dirty.