I asked how to get rid of fruit flies a week or so ago, and was told pretty much the same thing... get rid of the dead (I'm pretty good at picking up poop already) crickets, and the fruit flies will go away. I cleaned out the cage, and have been feeding 3-4 crickets daily instead of 6-10 every 2-3 days. I also started buying medium crickets so they would hopefully live longer.
The fly population decreased by 60% the day I cleaned the tank (mostly dispersing throughout the house) and have since dropped down to practically nothing. There's still a fly here and there, but they don't swarm out the top when I mist the cage anymore. Its a HUGE improvement, and occurred much faster than I had expected. No more flies in the cage, and best of all, no more flies in the house either!!!!!