I don't think so. I Bought some decks a while back and tried putting weights in the warped side and let it sit there for weeks. No real progress that I was successful with.
Maybe others have some suggestions. Or maybe nothing can be done.
Have you tried heating them up slightly with a hair dryer before weighting them down? It might take several rounds of this, and also do not overheat the cards because the plastic will melt and the ink might run. Try taking the entire deck and heating each of the sides.
Also, when you weight them down, don't have the cards straight - |. Instead weight them down the opposite of the direction they bend => if this ( then arrange them like this => ) and put the weight only in the middle section. Understand?
Once they're warped it takes "even" heat + humidity + weight + time. Can sometimes work but it's not an easy task.
Wouldn't recommend the hair dryer, doesn't take but a little bit too much heat from a hair dryer to ruin the cards (speaking from experience on this one)
I have access to a steam box. It might be possible to figure out a method of straightening warped cards It would probably be best to practice on bad decks first.