Actually shiny charm works a lot...yesterday while I was ev training my shiny 6iv greninja...I use sweet scent to lure a horde...and I get two shiny gligar...and shiny charm also work in mm too...728 eggs hatches...2 shiny greninja...
I didn't mean that the shiny charm doesn't work, it just doesn't seem to be giving me any luck with breeding x_x I'm nearing 1500 eggs now and no shiny, however yesterday I took a break to practice chaining with the pokeradar and I was able to get a shiny ducklett at a chain of 15. I definitely think it influenced that.