I know that one cannot gain "Hana'ah" from meat and dairy mixtures. I understood the term "hana'ah" to mean "pleasure" or "benefit".
My neighbor makes wonderful-smelling Italian cooking. The smell wafts through the building walls, into the hallways, etc. It's almost impossible to avoid the smell, and most of the time it smells good. But, I can't exactly ignore the smell of her lasagna (I know what she cooks b/c I ask her.) which has meat sauce and cheese. Do I have to wear a clothes pin on my nose to avoid "hana'ah"? I don't know if they make such large clothes pins, nowadays!