We did the same as you cos they don't need it everyday.
we do every other day with soap and the other days just a soothing warm bath no soap because baths are part of his night routine
I believe it should be everyday but I have a daughter. I wash her vag every morning and usually have showers afternoons or evenings. I always apply Aquafor and moisturizing lotion
Everyday as part of his bedtime routine . Wash his butt and penis every morning.
Totally up to you, we bath our baby everyday for the most part and use a good moisturizing lotion and I haven’t noticed his skin being dry.