There is a very safe way to clone in crystal that i have done loads of times and gotten alot of certain useful TMs. However, it does not work in gold/silver. I deleted my friend's best pokemon by trying it on G/S. What you do first is save, go into an empty box, deposit two pokemon(it has to be two, no more, no less), then, when you change to box six, switch off the power when it says not to. When you get back in, you will have the real ones in yuor party and the clones in the box you started with.