Hello all, Uno turned 12 weeks today and I need to clean his ears. He has a little bit of buildup since I last washed them last week, but i'm not sure what the best way to do it is...With his small ears I feel like i'm going to hurt him!!! What do you guys use to clean your pups ears well? I want to get deep down but don't want to risk damaging anything

help??
p.s. when I cleaned them before I took a puppy-bath cloth and cut it into a small square and just cleaned his ear that way...