Well I was told that by my Dermatologist, milk is a opaque fluid secreted from the mammilary glands. Never said MILK secretes thru ur skin. OIL does.lol Which WITH dirt will clog ur pores. Im just giving input on what works for me. No Dairy No AcneMilk isn't a mucus, nor is it secreted through your skin and it won't clog your pores up. Dietary allergies can cause skin issues though, so it's good to cut out things that could be factors (like milk).