You would need a pretty heavy emitting humidifier in order to get the mist to saturate the leaves. I suppose it could work if you weren’t using an exhaust. But I believe putting anything other than water in your humidifier would eventually break it. Mine says to only use purified water to maximize life of the unit, but I’ve been using tap and I’m already 6 months in.
If you must foliar feed, you should use an alkaline solution so as to avoid creating an acidic environment on the plant that would favor the development of powdery mildew.