Opportunistic feeders, their diet varies from one region to another. In the Antarctic, killer whales eat about 67% fishes, 27% marine mammals, and 6% squids. Killer whales in the Bering Sea (near Alaska) eat about 65% fishes, 20% squids, and 15% marine mammals.
Even though your shower grout looks dry, using it too early or sealing it before it's ready may damage it, leading to premature failure. Most cement-based grouts require a cure time of 48 to 72 hours before applying a penetrating sealer.
Usually directions tell us to grout within 16-24 hours when using sealer as a grout release. I would grout 2-10 hours after applying the sealer to be safe. After grouting, do the final cleanup either the next day or a few day later to allow the grout to cure. You can apply sealer on the tiles and grout after waiting at least 3 days.