Just leave them be. They'll be fine. If you're worried about them escaping just make sure the tub is secure and they can't get out. You'll only be gone 3 days, so its no biggie.
Should I put little bowl of water in there just in case they hatch?
I know the humidity won't be a bad thing, but would the perlite cause any problems or irritation? Should I put the eggs on paper towels before I leave?