Halve zucchini lengthwise, if they're small (about 6 inches). For larger ones, simply cut into 6-inch spears.
Combine oil and remaining ingredients, except flake sea salt, in a shallow dish. Add zucchini, tossing to coat. Let stand 10 minutes.
Preheat grill.
Remove zucchini from marinade, reserving marinade. Grill zucchini 10 minutes, or until tender, turning frequently. Transfer to a serving platter. Drizzle with any leftover marinade, and sprinkle with flake sea salt.