I use tollyjoy anti-dustmite laundry detergent for my kids. That’s the only laundry detergent that is suitable for them so far. What shower gel are you using for your son? Have to ensure that it’s soap free too. As for moisturiser, I think you’ll really have to trial and error to see which suits him better.
you can use hypoallergenic soaps po, we use human nature baby bath and i put a little VCO on his scalp before taking a bath.
ang