Good luck to you. If you see any fungus gnats around your remaining cuttings, it may be too late. One adult can lay thousands of eggs. They love damp soil, and I learned to put an inch of sand on top. They hate sand, but will enter through holes at the bottom too. When the eggs hatch, the larvae eat roots to survive. Then they suddenly start hatching and you may see swarms of adults flying around.
When I water, I use BT in the water, which kills the larvae. I just got so over fungus gnats, I only root mine outside in dirt now. They don't bother those cuttings.
Suzi