I have no more gnats thanks to the spiders and anoles that are in the GH.
I wish I could mist every day but alas, the working girl cannot have such luxury. I will look into putting my mister on a timer. I have one of those wire misters that you can twist around things. We used it during a 4thof July party so that people could cool off when walking under the arbor. I sprays a fine mist. If it works for people I think it will help in my greenhouse.