FUNGUS GNATS!!!

[Kailyn]

I hate these little flies, they were in some other plants and have recently been enjoying my phals. They LOVE my humidity trays. I know everyone is going to say water less but its unfortunately not an option (i let my avocado dry out for 2 days extra then normal and its leaves started falling off) also the gnats still are in the dry soil. I plan to repot everything but don't have any sphag available for my orchids. so my question is if i sterilize there current media in an oven will this work to kill the eggs /larva? Has anyone tried it with a mostly sphag but some bark/perlite combo? I have been trying all kinds of home remedies for these flies and am pretty fed up.