Had several RCBS dies stored in a flooded basement. I soaked them with naval jelly and scrubbed with steel wool, used a brush on a cleaning rod with a drill to polish the insides. Worked fine afterward. This would be a good time to hone the dies to your case dimensions as that will remove rust and result in an almost custom equivalent. I liked the BPCR blued dies so cold blued some of mine, seems to have helped. I always store the dies with a treatment of Corrosion X, Eesox or even Hornaday one shot case lube. I wipe the dies down with solvent or Kroil before using them. Wipe of and lube your dies and you shouldn't have any trouble.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli