The ocean is completely different than a small cube of water. You need to build a bacteria colony capable of breaking down your bio load's waste to a non-toxic point. This can be done easily without fish, and nothing needs to suffer. Or, you can use fish, like suggested, and torture them while you bacteria colony is growing.
The no fish way is better because it's more humane, and you probably don't want to keep damsels after the cycle is over, and they are difficult to catch. It's much easier to dump ammonia into the tank and just wait. Some toss in a raw cocktail shrimp and use that to start the cycle.
Using fish to cycle a tank does not make the cycle shorter.
