Best flattening swim binder or method?

I've been using an Untag basic swim binder and it works fine for swimming but absolutely does not make me flat. I'm a B/C cup and I need the best swim binder that'll make me flat. Idc abt mobility or safety or anything I just need a binder to swim in that will make me flat. What methods or binders should I get to help make me as flat as possible? My swim shirt always clings to me making my chest awfully obvious and I need to be able to swim and be stealth.