Considered to be "the opposite" of the Battle Tower Pokémon cloning glitch (Emerald), it allows the player to permanently delete Pokémon from a save file without the Release option, which cannot be used on Eggs and Bad Eggs.
Procedure

Go to the PC in the Battle Tower and save. Withdraw the Pokémon or Egg to be erased from Lanette's PC. Log Off of the computer and save the game. Deposit the Pokémon or Egg placed in the party during step 2.
