This is a case where prevention is worth a pound of cure. How much epoxy do you have to remove? Are you using oversize copper foil, or at least a release sheet that extends beyond the panel edges? Minimize the amount of epoxy on the plates first. This type of process only allows epoxy around the tooling holes. I have found the best method of removal is to coat the separator plates with a good mold release before layup. After breakdown, the residual epoxy around the holes can be scraped off quickly and easily (try a sharpened putty knife; it's safer than razor blades). If desired (we do), the plate can then be passed through a plate scrubber. We use Tadco Tuflube 3C, which is mixed with water and put in the rinse chamber of our plate scrubber. After breakdown, the operators quickly scrape the tooling holes and feed the plates into the scrubber. We use an Ishii Hyoki scrubber, and this does not degrade the surface of the plates. As the plates pass through the rinse, they are coated with mold release at the same time, dried, and returned to the lay-up room.