I will confess to having done something that is, I suspect, even riskier than the techniques already mentioned as ways to deal with impossibly curled (as well as "cupped") film: once the roll has dried, spool it with the emulsion side facing out (Patterson reels work very well here) then "heat" the reel with a blow-dryer set at its lowest heat setting, keeping the dryer moving slowly over the side of the reel for about 10 seconds and keeping it a safe distance away (6-8"). Flip the reel over and do the same to the other side. Let the film return to room temperature. Whenever I've done this, the rolls prove to be very "relaxed," in most cases laying perfectly flat or close to it, and easily printable/scannable. I haven't needed to do this for a while, since the films I usually shoot now behave themselves properly, but this was a technique that has in the past allowed me to use some rolls that were utterly resistant to being weighted down, or re-wetted and hung w/ a few extra ounces attached to the bottom weight, or anything else I could think of.
I've always half-suspected this might be heresy from an archival standpoint, but then again using blowdryers to dry films is, or at least used to be, considered a reasonable if not common practice.
Proceed, as always, at your own risk.