Yes, it still works! I know someone that got a shiny Fennekin after 500+ eggs, but a shiny Chespin after only 30+ or so.
You just have to have patience. It's really lucky to get one in one box, and the only reason you see so many people that are is because people make one box, and give up!
Also a tip; go catch a Fletchling and evolve it to Fletchinder (at level 17, it'll take 10 mins tops). Now, have Fletchinder in your party while you hatch eggs - it has Flame Body, which HALVES the steps an egg takes to hatch! It sped up my Eevee hatching lol!