Awhile ago I bought a cheap Genco Registered on e-bay to practice my honing.
It was slightly warped, but I've managed to got a good edge on it and had a nice shave.
I've decided to buy a new one and got Ontario made by Genco.
Condition of the new razor was excellent, except one thing ... it was warped even more then my first, cheap one.

Then I saw the Dovo video and notice one guy checking for warpage and correcting it with a hammer

I've put the razor on very heavy metal base and hit it firm but gently on spine multiply times until the warpage was gone. I don't see any marks on the razor, only on the hammer.
The razor was honed and provided very good shave.