So far I haven't found any way to get around the Duking Trade Glitch without cheating. I've also tried to use AR codes to change Pokémon found in Pokéspots, but XG is too modified to have any of those cheats work, sadly. You can use an AR code that lets you snag any Pokémon to get Croconaw at Pyrite from Commander Exol (or Feraligatr from Mt. Battle Areas 36 and 88 if you're past that point), Quilava at Pyrite from Cipher Peon Molly (or Typhlosion from Mt. Battle areas 29 and 30) and Meganium from Mt. Battle area 32 (there are no trainer owned Bayleef).
BTW, can anyone with 1.07 check to see if trading is doable? 1.07 save files work with the latest version so maybe it's a workaround? Then again, the link to download 1.07 is gone.