Yeah, it's kinda neat.
Once you get a shiny Number for the RNG in Emerald, you can get all of the SR shinies.
It's somewhat hard to do show, as shinyhunter on YouTube has gone through 22 profiles without a number.
You must get the number, and then you can SR for anything.
You must hit A while in front of the pokemon/starter bag/whatever you are getting the pokemon from, BEFORE the location bar drops down. In that 1 crappy second, you must do so. After 200 resets, you should find your shiny. If you dont' find a shiny starter by then, get a new profile. It's very hard for 200 freaking 1 second A hits, as I get nervous if I am gonna mess up or not...
So once you find your shiny, no need to use a master ball as long as you have 20 Timers and Ultras, but if you want to save yourself time, bring like 50 of each. If you kill it, just start SRing again, and you can find the shiny again within 200 resets (With a shiny number, you can find a shiny with a 1/200 chance in that 1 second, so you can find it at any time in there)