BT to the rescue!
So my 5 gal buckets outside were absolutely inundated with fungus gnats the last time I had checked on them. I got some of the BT on the left in the pic, and swirled about a tbs of it around in my watering mix about 3 days ago. Just checked today - and BAM... No more gnats! This stuff worked great.
The BT on the right actually shoots out of the container in a powdered spray form. I purchased this one after seeing a YouTube video with it used on peppers. I was also having a problem with critters eating up my leaves, but again - 3 days out from using it, and I've got no new holes munched in my leaves!
... Thus far there are no bad effects on the plants either, I'll chalk this one up as a win.