Here's how it works:
Reject the first 42 eggs. That means say no to the man when he has an egg. Let him keep it 42 times.
Take the 43rd egg, and each egg afterwards and hatch them until you get a shiny Pokemon
Encounter wild Pokemon
Encounter Trainers who want to battle
Turn off your game (unless you saved before taking a shiny egg)
Use the HM FLY or anything to change your position.
You can, however, still run up and down between Route 209 and Route 210 through Solaceon Town.
And that's really all there is to it, which makes a veteran shiny hunter like myself, upset.
Even though you still had to work and get good at the PokeRadar, using this Egg chaining thing makes shiny Pokemon seem obsolete. You can get the Starters, Riolu, ANYTHING THAT CAN BREED shiny using this method.
Heartbreaking, especially since it took me a week of SRing to get my shiny Totodile. Today, it might not even take me 2 days.
The odds are assumed to be the same as having 40 Pokemon in the chain while using the PokeRadar: 1 in 200.