Cut two 12-inch square sheets of aluminum foil.
Grease the shiny side of the foil with oil. Place two fillets side by side on each square, and fold up the outer edges.
Drizzle one tablespoon lime juice over each fillet. Season with salt, pepper and garlic.
Fold and pinch the aluminum foil extra tightly to create a watertight seal around each pair of fillets. Make sure the packet's airtight by pressing down on it gently with your hand. If air escapes easily, rewrap.
Place fish packets on the top rack.
Set dishwasher to the "normal" cycle. Most dishwashers have "economy" and "cool dry" settings, which are undesirable since they conserve heat. However, on the other end of the spectrum, the "pots and pans" setting tends to overcook the fish.
Run salmon through the entire wash-and-dry cycle -- approximately 50 minutes for most models.