How can I copy a master ball on pokemon?

how do you copy a master ball on leaf green?

I remember this glitch off silver, but unsure if it works on LG. Give a pokemon the item to hold and travel to the PKMN league. Goto a PC and change that pokemon with another in a box. While it is saving. Turn the power off half way through. If worked correctly, your Pokemon should have duplicated. And so should have the items!

that doesn't work in leaf green.

check out gamefaqs maybe they have somethin.