Not dumb at all, I've seen smoke fluid soaked boards that were none the worse for wear when cleaned off. I clean them with 99% Isopropyl Alcohol. I do know that steady exposure to smoke fluid will harden the insulation on wiring, I see lots of that. Smoke fluid is non-conductive, and most boards are washed during manufacture, so sealing should be a non-issue.
I have yet to personally see a board that has failed due to exposure to smoke fluid. I'd also like to know more about what and why this happens.