IMPOSSIBLE
Hax and gamesharx! In fact, they're the only way to get 999 or 99 rare candies or master balls.
you have to buy actionreplay and get lots of rare candies
by using a specific gameshark code that enables you to get 99 rare candies on ruby.
by cheat
Buy an action replay and set it to 999 rare candies
you give rare candies to 99 pokemons and trade them to heart gold... time consuming? yes, but it should work unless it doesnt allow you to trade pokemon holding rare candies.
action replay
action replay
Get a shuckle, give it an oran berry, wait a long time and it will be turned into a rare candy!
trades, AR or hacking
On Pokemon emerald, just clone 99 Pokemon holding a rare candy.
rare candies can only be found in certain places scatterd around shinoh only 8 are accessable To get 99 you have to cheat with a cheating device like AR or gameshark.