I have a team at level 100 and I want to EV train them from scratch, to do this, would it be worth it to use stat reducing berries to make all of their EVs 0 and train from there? If not, what would you advise? Oh, and I'm playing on White 2.
It's worth it only if you can get that many Berries :P if you can't, then just go as is, because there is no other way to reduce EVs. You could retrain new ones but that takes forever.
If the berry seller in join avenues rank is 10. Even if it is ,the only stat reducing berries are spec A ,spec D ,and speed. The berries also reduce 10 Evs per use. You would be better off training a new Pokemon unless you can get your hands on more stat reducing berries. Although you could also get a rank 10 grooming shop to reduce Evs to 0 but if your friendly with your Pokemon, they will refuse to groom it. Either way it's could be expensive.