I highly discourage you from attempting to debug a V4.5. Doing so would just put it into hyper-speed mode and will possibly break it, and that's no fun! I'm not sure if you can debug a V5. I don't have one, so I don't have much experience with it. As for the V6, check out this thread:
https://www.tamatalk.com/IB/index.php?showtopic=156214. It seems to be ongoing, not sure if it's been successfully done yet. The one that I've seen successfully debugged time and time again is the V3. I think
THIS VIDEO sums it up quite nicely. As always with debugging or any experimentation with a Tamagotchi, please proceed at your own risk. Good luck!