Comment below that Asian earwax is different is right. Also, ear cleaning is kind of sign of affection in Japan - wife cleaning husband's ears and so on. There are even parlors where men can go to have their ears cleaned by lovely ladies - with the same kind of posture as the two have in this episode. Apparently it can be very... pleasurable. Also it takes some practice to do it properly without causing damage - practice that in the west only certain medical professionals seem to have. You may consider it icky but thereabouts the attitude is different.
You can see another ear cleaning episode here: https://mangadex.org/chapter/181125/1