What can I use to wash off breast milk residue from my baby’s mouth

Depending how old baby is. I would use cotton wool pads and warm water.... Or a water wipe

You don't have to do that, breast milk has antibodies that protect your baby's mouth from bacteria, it doesn't need to be cleaned.

@Daniela oh okay then ,I was just trying to make sure he does not end up having an odour

I just wipe off his mouth with a muslin cloth, but don't use anything. If it was really on there I'd probably just use a dab of water on the cloth

I've just been wiping with a muslin cloth x