>>33745302You can also duplicate rare candies via cloning. It's pretty simple and impossible to fuck up.
1) Save in front of a PC
2) Deposit Pokemon with desired item in box.
3) Change boxes, and during the "Saving... Don't turn off the power" prompt, reset the game
4) You'll end up with the Pokemon you deposited in your party and in your box, giving you 2x of whatever it was holding
It works best with 5 Pokemon at a time, and you can just release them as soon as you're done duping stuff.