You cannot clone pokemon in sapphire, but you can in emerald, and I can tell you how it needs to be done at battle tower
Your first step is take the pokemon you want to clone and put it in any box, but make sure there is no other pokemon in that box.
Your second step is to exit your box and save your game
Your third step is to go back into the box, withdraw your pokemon you want to clone exit the box but don't save
Talk to the battle link lady and enter a link battle, when she asks you to give her two pokemon, give her two random, but not the one you want to clone!!
Is part is important to the cloning, when you enter the pokemon there is a Two second pause, DO NOT TURN YOUR POWER OFF THIS IS WHEN THE CLONING PROCESS IS GOING ON
After its done with the pause, and asks you to save, do not save but turn off the game off at that point
Turn it back on, go into the box you stored it in and viola!! You're cloned pokemon is there
MY experience is that I just tried it right now with my kyogre in emerald, and it worked fine, happy cloning!
Your first step is take the pokemon you want to clone and put it in any box, but make sure there is no other pokemon in that box.
Your second step is to exit your box and save your game
Your third step is to go back into the box, withdraw your pokemon you want to clone exit the box but don't save
Talk to the battle link lady and enter a link battle, when she asks you to give her two pokemon, give her two random, but not the one you want to clone!!
Is part is important to the cloning, when you enter the pokemon there is a Two second pause, DO NOT TURN YOUR POWER OFF THIS IS WHEN THE CLONING PROCESS IS GOING ON
After its done with the pause, and asks you to save, do not save but turn off the game off at that point
Turn it back on, go into the box you stored it in and viola!! You're cloned pokemon is there
MY experience is that I just tried it right now with my kyogre in emerald, and it worked fine, happy cloning!